tp_base_connection_change_status: don't unref and set to 0 the self-handle when connection is disconnected (fd.o #17751)
tp_base_connection_change_status: don't unref and set to 0 the self-handle when connection is disconnected (fd.o #17751)

There is no reason to unref it at this stage and this make CM unable to
use the self-handle during the disconnection.
There is already code to unref it when the BaseConnection disposes so we
don't need any other change.

Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib,Distrotech/telepathy-glib