Do switch connection monitoring for failed connections as well

This will allow the agent to create the connection object at
start and forget about trying to re-connect it in case the
switch is not available when the agent starts.

Change-Id: I262e8741033a7a2ad6d7f48456a14a3d6da19d05
Signed-off-by: Amit Bose <bose@noironetworks.com>