attrib: Don't attempt to unregister event id 0
attrib: Don't attempt to unregister event id 0

Id 0 is considered invalid so the code should not even try to lookup for
it in the event list instead print a warning and return FALSE
immediatelly.

mapfau/bluez,pstglia/external-bluetooth-bluez,ComputeCycles/bluez,ComputeCycles/bluez,pkarasev3/bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,pkarasev3/bluez,pstglia/external-bluetooth-bluez,pkarasev3/bluez,silent-snowman/bluez,pkarasev3/bluez,silent-snowman/bluez,pstglia/external-bluetooth-bluez,ComputeCycles/bluez,mapfau/bluez,mapfau/bluez,ComputeCycles/bluez,silent-snowman/bluez,silent-snowman/bluez