fix bug about field misspell (#243)

### 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/242)]

### Type of change

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

api/db/init_data.py

     for llm in LLMService.query(fid=LLM_FACTORY):
         tenant_llm.append(
             {"tenant_id": user_info["id"], "llm_factory": LLM_FACTORY, "llm_name": llm.llm_name, "model_type": llm.model_type,
-             "api_key": API_KEY, "base_url": LLM_BASE_URL})
+             "api_key": API_KEY, "api_base": LLM_BASE_URL})
 
     if not UserService.save(**user_info):
         print("\033[93m【ERROR】\033[0mcan't init admin.")