MINOR: stats: report the load balancing algorithm in CSV output

It was already present in the HTML output, let's add it to CSV now,
but only when SHLGNDS is set.
diff --git a/doc/management.txt b/doc/management.txt
index 83c7a34..5edfaab 100644
--- a/doc/management.txt
+++ b/doc/management.txt
@@ -1025,6 +1025,7 @@
  73. addr [L..S]: address:port or "unix". IPv6 has brackets around the address.
  74: cookie [..BS]: server's cookie value or backend's cookie name
  75: mode [LFBS]: proxy mode (tcp, http, health, unknown)
+ 76: algo [..B.]: load balancing algorithm
 
 
 9.2. Unix Socket commands
diff --git a/src/dumpstats.c b/src/dumpstats.c
index 504bba1..386c464 100644
--- a/src/dumpstats.c
+++ b/src/dumpstats.c
@@ -336,6 +336,7 @@
 	ST_F_ADDR,
 	ST_F_COOKIE,
 	ST_F_MODE,
+	ST_F_ALGO,
 
 	/* must always be the last one */
 	ST_F_TOTAL_FIELDS
@@ -422,6 +423,7 @@
 	[ST_F_ADDR]           = "addr",
 	[ST_F_COOKIE]         = "cookie",
 	[ST_F_MODE]           = "mode",
+	[ST_F_ALGO]           = "algo",
 };
 
 /* one line of stats */
@@ -3751,7 +3753,7 @@
 		if (flags & ST_SHLGNDS) {
 			/* balancing */
 			chunk_appendf(&trash, "<div class=tips>balancing: %s",
-			              backend_lb_algo_str(px->lbprm.algo & BE_LB_ALGO));
+			              field_str(stats, ST_F_ALGO));
 
 			/* cookie */
 			if (stats[ST_F_COOKIE].type) {
@@ -4346,9 +4348,11 @@
 	stats[ST_F_TYPE]     = mkf_u32(FO_CONFIG|FS_SERVICE, STATS_TYPE_BE);
 	stats[ST_F_RATE]     = mkf_u32(0, read_freq_ctr(&px->be_sess_per_sec));
 	stats[ST_F_RATE_MAX] = mkf_u32(0, px->be_counters.sps_max);
+
 	if (flags & ST_SHLGNDS) {
 		if (px->cookie_name)
 			stats[ST_F_COOKIE] = mkf_str(FO_CONFIG|FN_NAME|FS_SERVICE, px->cookie_name);
+		stats[ST_F_ALGO] = mkf_str(FO_CONFIG|FS_SERVICE, backend_lb_algo_str(px->lbprm.algo & BE_LB_ALGO));
 	}
 
 	/* http response: 1xx, 2xx, 3xx, 4xx, 5xx, other */