fix docker compose issue (#238)

### What problem does this PR solve?

_Briefly describe what this PR aims to solve. Include background context
that will help reviewers understand the purpose of the PR._

Issue link:#[[Link the issue
here](https://github.com/infiniflow/ragflow/issues/226)]

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)

rag/llm/chat_model.py

@@ -170,3 +170,4 @@ class LocalLLM(Base):
             return ans, num_tokens_from_string(ans)
         except Exception as e:
             return "**ERROR**: " + str(e), 0
+