MINOR: stats: improve max stats descriptions

In order to unify prometheus and stats description, we need to remove
some field reference which are specific to stats implementation:
- `scur` in max current sessions (also reword current session)
- `rate` in max sessions
- `req_rate` in max requests
- `conn_rate` in max connections

Signed-off-by: William Dauchy <wdauchy@gmail.com>
diff --git a/src/stats.c b/src/stats.c
index fdb8e9a..6fa59a9 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -160,8 +160,8 @@
 	[ST_F_SVNAME]                        = { .name = "svname",                      .desc = "Server name" },
 	[ST_F_QCUR]                          = { .name = "qcur",                        .desc = "Number of current queued connections" },
 	[ST_F_QMAX]                          = { .name = "qmax",                        .desc = "Highest value of queued connections encountered since process started" },
-	[ST_F_SCUR]                          = { .name = "scur",                        .desc = "Current number of sessions on the frontend, backend or server" },
-	[ST_F_SMAX]                          = { .name = "smax",                        .desc = "Highest value of scur encountered since process started" },
+	[ST_F_SCUR]                          = { .name = "scur",                        .desc = "Number of current sessions on the frontend, backend or server" },
+	[ST_F_SMAX]                          = { .name = "smax",                        .desc = "Highest value of current sessions encountered since process started" },
 	[ST_F_SLIM]                          = { .name = "slim",                        .desc = "Frontend/listener/server's maxconn, backend's fullconn" },
 	[ST_F_STOT]                          = { .name = "stot",                        .desc = "Total number of sessions since process started" },
 	[ST_F_BIN]                           = { .name = "bin",                         .desc = "Total number of request bytes since process started" },
@@ -191,7 +191,7 @@
 	[ST_F_TYPE]                          = { .name = "type",                        .desc = "Type of the object (Listener, Frontend, Backend, Server)" },
 	[ST_F_RATE]                          = { .name = "rate",                        .desc = "Total number of sessions processed by this object over the last second (sessions for listeners/frontends, requests for backends/servers)" },
 	[ST_F_RATE_LIM]                      = { .name = "rate_lim",                    .desc = "Limit on the number of sessions accepted in a second (frontend only, 'rate-limit sessions' setting)" },
-	[ST_F_RATE_MAX]                      = { .name = "rate_max",                    .desc = "Highest value of 'rate' observed since the worker process started" },
+	[ST_F_RATE_MAX]                      = { .name = "rate_max",                    .desc = "Highest value of sessions per second observed since the worker process started" },
 	[ST_F_CHECK_STATUS]                  = { .name = "check_status",                .desc = "Status report of the server's latest health check, prefixed with '*' if a check is currently in progress" },
 	[ST_F_CHECK_CODE]                    = { .name = "check_code",                  .desc = "HTTP/SMTP/LDAP status code reported by the latest server health check" },
 	[ST_F_CHECK_DURATION]                = { .name = "check_duration",              .desc = "Total duration of the latest server health check, in milliseconds" },
@@ -203,7 +203,7 @@
 	[ST_F_HRSP_OTHER]                    = { .name = "hrsp_other",                  .desc = "Total number of HTTP responses with status <100, >599 returned by this object since the worker process started (error -1 included)" },
 	[ST_F_HANAFAIL]                      = { .name = "hanafail",                    .desc = "Total number of failed checks caused by an 'on-error' directive after an 'observe' condition matched" },
 	[ST_F_REQ_RATE]                      = { .name = "req_rate",                    .desc = "Number of HTTP requests processed over the last second on this object" },
-	[ST_F_REQ_RATE_MAX]                  = { .name = "req_rate_max",                .desc = "Highest value of 'req_rate' observed since the worker process started" },
+	[ST_F_REQ_RATE_MAX]                  = { .name = "req_rate_max",                .desc = "Highest value of http requests observed since the worker process started" },
 	[ST_F_REQ_TOT]                       = { .name = "req_tot",                     .desc = "Total number of HTTP requests processed by this object since the worker process started" },
 	[ST_F_CLI_ABRT]                      = { .name = "cli_abrt",                    .desc = "Total number of requests or connections aborted by the client since the worker process started" },
 	[ST_F_SRV_ABRT]                      = { .name = "srv_abrt",                    .desc = "Total number of requests or connections aborted by the server since the worker process started" },
@@ -234,7 +234,7 @@
 	[ST_F_MODE]                          = { .name = "mode",                        .desc = "'mode' setting (tcp/http/health/cli)" },
 	[ST_F_ALGO]                          = { .name = "algo",                        .desc = "Backend's load balancing algorithm, shown only if show-legends is set, or at levels oper/admin for the CLI" },
 	[ST_F_CONN_RATE]                     = { .name = "conn_rate",                   .desc = "Number of new connections accepted over the last second on the frontend for this worker process" },
-	[ST_F_CONN_RATE_MAX]                 = { .name = "conn_rate_max",               .desc = "Highest value of 'conn_rate' observed since the worker process started" },
+	[ST_F_CONN_RATE_MAX]                 = { .name = "conn_rate_max",               .desc = "Highest value of connections per second observed since the worker process started" },
 	[ST_F_CONN_TOT]                      = { .name = "conn_tot",                    .desc = "Total number of new connections accepted on this frontend since the worker process started" },
 	[ST_F_INTERCEPTED]                   = { .name = "intercepted",                 .desc = "Total number of HTTP requests intercepted on the frontend (redirects/stats/services) since the worker process started" },
 	[ST_F_DCON]                          = { .name = "dcon",                        .desc = "Total number of incoming connections blocked on a listener/frontend by a tcp-request connection rule since the worker process started" },