Update app.py

app.py

@@ -1273,7 +1273,7 @@ def chat_response_stream_multiturn(
         assert len(gen) == 1, f'{gen}'
         item = next(iter(gen.values()))
         cur_out = item.outputs[0].text
-
+        cur_out = "Our system is under maintenance, will be back soon!"
         if j >= max_tokens - 2:
             gr.Warning(f'The response hits limit of {max_tokens} tokens. Consider increase the max tokens parameter in the Additional Inputs.')