manage branch in redirect

* adds x-headers if the call is redirected to another media server

kamailio/default.cfg

@@ -818,6 +818,7 @@ route[INTERNAL_REDIRECT]
         xlog("L_INFO", "$ci|log|found redirect for $var(redirect) : $var(prefered_route)\n");
         $du = $var(prefered_route);
         $avp(AVP_REDIRECT_KEY) = $var(redirect);
+        t_on_branch("MANAGE_BRANCH");
         t_on_reply("INTERNAL_REPLY");
         t_on_failure("INTERNAL_FAULT");
         t_set_fr(0, 1000);