fix set_api_key bug (#191)

### 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]

### Type of change

- [x] Bug Fix (non-breaking change which fixes an issue)
- [ ] New Feature (non-breaking change which adds functionality)
- [ ] Breaking Change (fix or feature that could cause existing
functionality not to work as expected)
- [ ] Documentation Update
- [ ] Refactoring
- [ ] Performance Improvement
- [ ] Test cases
- [ ] Python SDK impacted, Need to update PyPI
- [ ] Other (please describe):

api/apps/llm_app.py

@@ -45,7 +45,7 @@ def set_api_key():
     for llm in LLMService.query(fid=factory):
         if llm.model_type == LLMType.EMBEDDING.value:
             mdl = EmbeddingModel[factory](
-                req["api_key"], llm.llm_name, req.get("base_url"))
+                req["api_key"], llm.llm_name, base_url=req.get("base_url"))
             try:
                 arr, tc = mdl.encode(["Test if the api key is available"])
                 if len(arr[0]) == 0 or tc == 0:
@@ -54,7 +54,7 @@ def set_api_key():
                 msg += f"\nFail to access embedding model({llm.llm_name}) using this api key." + str(e)
         elif not chat_passed and llm.model_type == LLMType.CHAT.value:
             mdl = ChatModel[factory](
-                req["api_key"], llm.llm_name, req.get("base_url"))
+                req["api_key"], llm.llm_name, base_url=req.get("base_url"))
             try:
                 m, tc = mdl.chat(None, [{"role": "user", "content": "Hello! How are you doing!"}], {
                                  "temperature": 0.9})