Update app.py

app.py

@@ -20,7 +20,10 @@ Join us : 🌟TeamTonic🌟 is always making cool demos! Join our active builder
 @spaces.GPU
 def whisper_speech_demo(text, lang, speaker_audio, mix_lang, mix_text):
     pipe = Pipeline()
-    speaker_url = speaker_audio if speaker_audio else None
+    speaker_url = None
+
+    if speaker_audio is not None:
+        speaker_url = speaker_audio
 
     if mix_lang and mix_text:
         mixed_langs = lang.split(',') + mix_lang.split(',')