Agent crash@ route notify

Agent channel is deleted and notify is received on same.
It can happen that notify was enqueued before unregister/delete of channel.
Solution is to ignore if any notify comes for inactive channel.
Same is present in handling of vrf notify (controller_vrf_export).

Change-Id: I1a791b5411841c5a72b7f83b414992a014e2b6f7
Closes-bug: #1668205

src/vnsw/agent/controller/controller_export.cc

@@ -131,6 +131,11 @@ void RouteExport::Notify(const Agent *agent,
             return;
     }
 
+    //If channel is no more active, ignore any updates.
+    //It may happen that notify is enqueued before channel is removed.
+    if (!AgentXmppChannel::IsBgpPeerActive(agent, bgp_xmpp_peer))
+        return;
+
     if (route->is_multicast()) {
         MulticastNotify(bgp_xmpp_peer, associate, partition, e);
     } else {