UPNP Connectivity Change - Perform a full restart only on actual change

In the current implementation of UPNP, upon reception of the "connectivity change" notification, a full restart of the provisioning process is performed. Meaning that all existing provisioned mappings will be removed and requested anew. The notification can be sent on various connectivity activities which do not always result in an actual connectivity change (change of the local and/or access point addresses). To prevent performing unnecessary processing, the upnp-context must first perform a check on the connectivity before performing a full restart.