Update app.py

app.py

@@ -37,10 +37,13 @@ def respond(
         top_p=top_p,
     ):
         token = message.choices[0].delta.content
-
-        response += token
+        if token is not None:
+            response += token
         yield response
 
+
+
+
 """
 For information on how to customize the ChatInterface, peruse the gradio docs: https://www.gradio.app/docs/chatinterface
 """