fix value

app.py

@@ -1323,7 +1323,7 @@ def audio_diarization_task(task_json, num_speakers):
     
     result = transcriber.process_audio_diarization(
             task_json=task_json,
-            num_speakers=num_speakers if num_speakers > 0 else None,
+            num_speakers=num_speakers if num_speakers > 0 else 0,
         )
     #formatted_output = format_segments_for_display(result)
     return "OK", result