Do not log the gpt4all chat response stream in khoj backend

Stream floods stdout and does not provide useful info to user

src/khoj/processor/conversation/gpt4all/chat_model.py

@@ -163,6 +163,5 @@ def llm_thread(g, messages: List[ChatMessage], model: GPT4All):
     prompted_message = templated_system_message + chat_history + templated_user_message
     response_iterator = model.generate(prompted_message, streaming=True, max_tokens=2000)
     for response in response_iterator:
-        logger.info(response)
         g.send(response)
     g.close()