BUG/MEDIUM: checks: a server passed in maint state was not forced down.

Setting a server in maint mode, the required next_state was not set
before calling the 'lb_down' function and so the system state was never
commited.

This patch should be backported in 1.8
diff --git a/src/server.c b/src/server.c
index 23e4cc9..a37e919 100644
--- a/src/server.c
+++ b/src/server.c
@@ -4630,10 +4630,11 @@
 		else {	/* server was still running */
 			check->health = 0; /* failure */
 			s->last_change = now.tv_sec;
+
+			s->next_state = SRV_ST_STOPPED;
 			if (s->proxy->lbprm.set_server_status_down)
 				s->proxy->lbprm.set_server_status_down(s);
 
-			s->next_state = SRV_ST_STOPPED;
 			if (s->onmarkeddown & HANA_ONMARKEDDOWN_SHUTDOWNSESSIONS)
 				srv_shutdown_streams(s, SF_ERR_DOWN);