Update app.py

app.py

@@ -666,7 +666,7 @@ def run_demo(
     if model_paths is None:
         model_paths = {
             "VibeVoice-Large": "microsoft/VibeVoice-Large",
-            "VibeVoice-1.1B": "microsoft/VibeVoice-1.1B"
+            "VibeVoice-1.5B": "microsoft/VibeVoice-1.5B"
         }
 
     set_seed(42)