BUG/MEDIUM: servers state: server port is used uninitialized

Nenad spotted that the last fix was unfortunately wrong. Needs to be
backported to 1.6 as well.
diff --git a/src/server.c b/src/server.c
index ab309ab..3a04d22 100644
--- a/src/server.c
+++ b/src/server.c
@@ -2162,7 +2162,7 @@
 					int port;
 
 					/* save the port, applies the new IP then reconfigure the port */
-					get_host_port(&srv->addr);
+					port = get_host_port(&srv->addr);
 					srv->addr.ss_family = addr.ss_family;
 					str2ip2(params[0], &srv->addr, srv->addr.ss_family);
 					set_host_port(&srv->addr, port);