Only send notifications on uuid device_id's

Neutron assumes that all ports with the device_owner that start with
'compute:' are ports created by nova compute. Thus, when the debug agent
creates a port with device_owner = compute:probe the nova notifier
feature tells nova when this port is wired even though nova does not know
about it (doesn't really matter we just log an error). This patch adds a check
to make sure the device_id is a uuid as nova only uses uuids and the debug
agent uses the hostname for device_id.

Change-Id: I04e7195a1fb30bc37e1c0141315c053174f8722c
Closes-bug: #1288582
Merge "Only send notifications on uuid device_id's"