Update app.py

app.py

@@ -47,7 +47,7 @@ visit_webpage=VisitWebpageTool()
 model = HfApiModel(
 max_tokens=2096,
 temperature=0.5,
-model_id='mistralai/Mixtral-8x7B-Instruct-v0.1',# it is possible that this model may be overloaded
+model_id='gpt2',# it is possible that this model may be overloaded
 custom_role_conversions=None,
 )