Update app.py

app.py

@@ -40,7 +40,7 @@ async def generate(
     tokenizer = tokenizers[model_choice]
     
     conversation = [{"role": "system", "content": system_prompt}] if system_prompt else []
-    conversation += [{"role": "user", "content": user}, {"role": "assistant", "content": assistant} for user, assistant in chat_history]
+    conversation.extend([{"role": "user", "content": user}, {"role": "assistant", "content": assistant}] for user, assistant in chat_history)
     conversation.append({"role": "user", "content": message})
 
     input_ids = tokenizer(conversation, return_tensors="pt", truncation=True, max_length=MAX_INPUT_TOKEN_LENGTH).input_ids