Posting multiple OVSDB nodes with different node-id but same connection-info does not clean operational MD-SAL

If an active OVSDB connection is made via the config MD-SAL to the same
OVS host (IP address, port number) multiple times with different node-ids
then:

1. multiple entries are made in the config MD-SAL - 1 for each node-id
2. multiple sets of entries are made in the operational MD-SAL - 1 set for each node-id

If the config MD-SAL entries are then deleted, then:

1. All of the config MD-SAL entries are removed
2. Only the most recent operational MD-SAL set is removed. The older operational MD-SAL sets of entries corresponding to the config entry node-ids entered prior to the last one remain in the operational MD-SAL.

Better behavior could be:
1. don't allow a new config MD-SAL entry to be made to the same connection-info if there is already a config MD-SAL entry for the connection.

2. Or, allow the new config MD-SAL entry, but make sure to delete the old operational MD-SAL information.

3. Or, ... ?