KAM-10 ignore OPTIONS method

(cherry picked from commit b01055b90f)

kamailio/antiflood-role.cfg

@@ -65,6 +65,8 @@ route[ANTIFLOOD_AUTH_LIMIT]
         return(1);
     }
 
+    if (is_method("OPTIONS")) return(1);
+
     $var(auth_key) = "";
     if($sel(cfg_get.kazoo.antiflood_failed_auth_use_port) == 1) {
         $var(auth_key) = $_s("$Au::$si::$sp");