Update app.py

app.py

@@ -120,7 +120,7 @@ async def on_message(msg: cl.Message):
     
     if stream:
         await process_stream(stream, msg=stream_msg)
-        message_history.append({"role": "system", "content": stream_msg.content})
-        image_history.append({"role": "system", "content": stream_msg.content})
+        message_history.append({"role": "assistant", "content": stream_msg.content})
+        image_history.append({"role": "assistant", "content": stream_msg.content})
 
     return stream_msg.content