gobex: Protect against user callback freeing internal objects
gobex: Protect against user callback freeing internal objects

A user callback could potentially do things like g_obex_cancel_request
or g_obex_unref while we are inside the IO watch callback. It is
therefore important to ensure that we are in a consistent state when the
user callback returns.

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