fix streaming None object (openai sdk)

chat_demo.py

@@ -57,10 +57,11 @@ def openai_call(message, history, system_prompt, max_new_tokens):
     )
     reply = ""
     for chunk in response:
-        delta = chunk.choices[0].delta.content
-        if delta is not None:
-            reply = reply + delta
-            yield reply, None
+        if len(chunk.choices) > 0:
+            delta = chunk.choices[0].delta.content
+            if delta is not None:
+                reply = reply + delta
+                yield reply, None
     history.append({ "role": "assistant", "content": reply })
     yield reply, gr.State(history)
 
@@ -97,7 +98,7 @@ with gr.Blocks() as demo:
         type="messages",
         additional_inputs=[
             gr.Textbox("You are a helpful AI assistant.", label="System Prompt"),
-            gr.Slider(30, 8192, label="Max new tokens"),
+            gr.Slider(30, 8192, value=2048, label="Max new tokens"),
         ],
         additional_outputs=[conv_state],
         title="Edge level LLM Chat demo",