Update app.py

app.py

@@ -139,8 +139,8 @@ with demo:
             )
 
 def handle_pdb(sig, frame):
-    import pdb
-    pdb.Pdb().set_trace(frame)    
+    import pdb;
+    pdb.set_trace()
 
 if __name__ == "__main__":
     # Launch demo