fix: dialect_drop_down error bug

app.py

@@ -55,7 +55,7 @@ def automatic_speech_recognition(model_id: str, dialect_id: str, audio_data: str
 def when_model_selected(model_id: str):
     model_config = models_config[model_id]
 
-    if "dialect_mapping" not in model_config["dialect_mapping"]:
+    if "dialect_mapping" not in model_config:
         return gr.update(visible=False)
 
     dialect_drop_down_choices = [