[Question]: 在chat页面返回的结果出现截断

### Describe your problem

[ragflow](https://github.com/infiniflow/ragflow/tree/main)/[api](https://github.com/infiniflow/ragflow/tree/main/api)/[db](https://github.com/infiniflow/ragflow/tree/main/api/db)/[services](https://github.com/infiniflow/ragflow/tree/main/api/db/services)
/dialog_service.py 第81行代码可能会导致返回的结果出现截断