BUG/MINOR: stats: fix be/sessions/current out in typed stats

"scur" was typed as "limit" (FO_CONFIG) and "config value" (FN_LIMIT).
The real types of "scur" are "metric" (FO_METRIC) and "gauge"
(FN_GAUGE). FO_METRIC and FN_GAUGE are the value 0.
diff --git a/src/stats.c b/src/stats.c
index 976496e..b0c0fc5 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -1501,7 +1501,7 @@
 	stats[ST_F_MODE]     = mkf_str(FO_CONFIG|FS_SERVICE, proxy_mode_str(px->mode));
 	stats[ST_F_QCUR]     = mkf_u32(0, px->nbpend);
 	stats[ST_F_QMAX]     = mkf_u32(FN_MAX, px->be_counters.nbpend_max);
-	stats[ST_F_SCUR]     = mkf_u32(FO_CONFIG|FN_LIMIT, px->beconn);
+	stats[ST_F_SCUR]     = mkf_u32(0, px->beconn);
 	stats[ST_F_SMAX]     = mkf_u32(FN_MAX, px->be_counters.conn_max);
 	stats[ST_F_SLIM]     = mkf_u32(FO_CONFIG|FN_LIMIT, px->fullconn);
 	stats[ST_F_STOT]     = mkf_u64(FN_COUNTER, px->be_counters.cum_conn);