Controller ignores switch, if no ports are present

Controller ignores switch, if no ports are present

 - At switch connection, InventoryServiceShim mistakenly skips to
   inform the global listeners if no ports are configured on the switch.
   This is not visible with software switches because they always
   advertise they have the OFLocal port active.
   Being Connection Service a listener of global inventory service,
   it will not get to know about the switch presence, and in subsequent
   queries from InventoryServiceShim it will reply the switch is not
   locally connected to this controller, causing Inventory Shim to
   not inform its upper layer listeners about the switch. Therefore
   no other controller service will get to know the switch is conencted.

Change-Id: I29f658cc2a84ab7aab2c19ae9fe4d5a33c0afe0c
Signed-off-by: Alessandro Boch <aboch@cisco.com>