Crash if no dbus notification interface
Created by: ricardomv
If the interface org.freedesktop.Notifications
does not exist the application crashes when trying to send a notification
(lollypop:4795): libnotify-WARNING **: Failed to connect to proxy
Traceback (most recent call last):
File "/usr/lib/python3.4/site-packages/lollypop/notification.py", line 65, in _update_track
self._notification.show()
GLib.Error: g-dbus-error-quark: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.freedesktop.Notifications was not provided by any .service files (2)