### What problem does this PR solve?
https://github.com/infiniflow/ragflow/issues/7407
Based on this context, I think there should be some reasons that let
some LLMs have a mismatch (add the wrong "@xxx"),
So I think when use fid can not fetch llm then tried to just use name
should can fetch it.
### Type of change
- [x] Bug Fix (non-breaking change which fixes an issue)