avahi: move mdns_unregister_service() to run_service()
avahi: move mdns_unregister_service() to run_service()

Currently, mdns_unregister_service() is called in mux_client_read_cb(),
however the code can exit the main loop from other places,
e.g. mux_size_read_cb().

So let's unregister the service at the end of run_service()
where we also stop the socket service.

Signed-off-by: Jakub Janků <e6d62f7189d9c45efd907e4f2baf6f535f551138@redhat.com>

GNOME/phodav,GNOME/phodav