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)

api/settings.py

@@ -91,6 +91,8 @@ default_llm = {
 }
 LLM = get_base_config("user_default_llm", {})
 LLM_FACTORY = LLM.get("factory", "Tongyi-Qianwen")
+LLM_BASE_URL = LLM.get("base_url")
+
 if LLM_FACTORY not in default_llm:
     print(
         "\33[91m【ERROR】\33[0m:",