fix: sound issue on linux

This fix solves an issue that may be due to a pyaudio/portaudio problem on
linux: the application was crashing when trying to directly close the audio
stream

audio.py

@@ -35,6 +35,7 @@ def __del__(self):
 
     def pause(self):
         if self.stream:
+            self.stream.stop_stream()
             self.stream.close()
             self.stream = None
         return self