Fix import from qtpy in notifierInit()

Author: g1itch

src/bitmessageqt/__init__.py

@@ -1434,7 +1434,7 @@ def _simple_notify(
         self._theme_player = get_plugin('notification.sound', 'theme')
 
         try:
-            from qtpy import QtMultimedia
+            from PyQt5 import QtMultimedia
             self._player = QtMultimedia.QSound.play
         except ImportError:
             _plugin = get_plugin(