qtvcp -screens options: don;t call shutdown() function

It's called automatically in qtvcp.py and calling it here duplicates things.

Author: c-morley

lib/python/qtvcp/widgets/screen_options.py

@@ -429,7 +429,6 @@ def closeEvent(self, event):
             elif answer:
                 if self.PREFS_ and self.play_sounds and self.shutdown_play_sound:
                     STATUS.emit('play-sound', self.shutdown_exit_sound_type)
-                self.QTVCP_INSTANCE_.shutdown()
                 event.accept()
             # cancel
             elif answer == False: