BUG/MINOR: server: Remove RMAINT from admin state when loading server state

The RMAINT admin state is dynamic and should be remove from the
srv_admin_state parameter when a server state is loaded from a server-state
file. Otherwise an erorr is reported, the server-state line is ignored and
the server state is not updated.

This patch should fix the issue #576. It must be backported as far as 1.8.

(cherry picked from commit eaab7325a797e61d16a80b2969ab5f9cbd9679c5)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/src/server.c b/src/server.c
index a3fce5a..68a5b98 100644
--- a/src/server.c
+++ b/src/server.c
@@ -2626,7 +2626,7 @@
 			/* inherited statuses will be recomputed later.
 			 * Also disable SRV_ADMF_HMAINT flag (set from stats socket fqdn).
 			 */
-			srv_admin_state &= ~SRV_ADMF_IDRAIN & ~SRV_ADMF_IMAINT & ~SRV_ADMF_HMAINT;
+			srv_admin_state &= ~SRV_ADMF_IDRAIN & ~SRV_ADMF_IMAINT & ~SRV_ADMF_HMAINT & ~SRV_ADMF_RMAINT;
 
 			if ((p == params[2]) || errno == EINVAL || errno == ERANGE ||
 			    (srv_admin_state != 0 &&