feat: optimize baichuan prompt (#988)

api/core/prompt/generate_prompts/baichuan_chat.json

@@ -8,6 +8,6 @@
     "pre_prompt",
     "histories_prompt"
   ],
-  "query_prompt": "用户：{{query}}\n助手：",
+  "query_prompt": "用户：{{query}}",
   "stops": ["用户："]
 }