fix add slef base url openai error (#1854)

### What problem does this PR solve?

### Type of change

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

api/apps/llm_app.py

@@ -48,7 +48,7 @@ def set_api_key():
                 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:
+                if len(arr[0]) == 0:
                     raise Exception("Fail")
                 embd_passed = True
             except Exception as e:
@@ -59,7 +59,7 @@ def set_api_key():
             try:
                 m, tc = mdl.chat(None, [{"role": "user", "content": "Hello! How are you doing!"}], 
                                  {"temperature": 0.9,'max_tokens':50})
-                if not tc:
+                if m.find("**ERROR**") >=0:
                     raise Exception(m)
             except Exception as e:
                 msg += f"\nFail to access model({llm.llm_name}) using this api key." + str(