Another variation of bz 3141 - mdsal southbound stops updating after del-manager

To recreate -

1. run "ovs-vsctl set-manager ptcp:6640" for a passive connection.
2. connect to node using postman put call.
3. Once node is connected, del-manager.
4. now rerun postman command from #2
5. delete node using postman call
6. run set-manager for passive connection
7. Rerun #2, the operational does not get populated.