Southbound plugin does not allow controller initiated re-connection,if the previous connection was terminated from switch side and not from controller side (through data store).

Steps to recreate the issue:

(1) Set OVS switch to listen in passive mode
(2) Fire restconf to controller to connect to the switch
(3) Delete manager of the OVS switch, this will terminate the connection
(4) Delete connection configuration from the data store
(5) Set manager in passive mode again for ovs switch
(6) Add the same configuration to data store again to re-connect to the switch.

Controller won't connect to the switch. Log message shows following log message
2016-03-16 00:57:09,240 | WARN | on-dispatcher-38 | OvsdbDataChangeListener | 163 - org.opendaylight.ovsdb.southbound-impl - 1.2.2.SNAPSHOT | Connection to device ConnectionInfo{getRemoteIp=IpAddress [_ipv4Address=Ipv4Address [_value=192.168.122.110], _value=[1, 9, 2, ., 1, 6, 8, ., 1, 2, 2, ., 1, 1, 0]], getRemotePort=PortNumber [_value=16640], augmentations={}} already exists. Plugin does not allow multiple connections to same device, hence dropping the request OvsdbNodeAugmentation{getConnectionInfo=ConnectionInfo{getRemoteIp=IpAddress [_ipv4Address=Ipv4Address [_value=192.168.122.110], _value=[1, 9, 2, ., 1, 6, 8, ., 1, 2, 2, ., 1, 1, 0]], getRemotePort=PortNumber [_value=16640], augmentations={}}}