Append Open API url postfix to endpoint_url

Author: moon

api/core/model_runtime/model_providers/openai_api_compatible/llm/llm.py

@@ -120,6 +120,8 @@ def validate_credentials(self, model: str, credentials: dict) -> None:
             endpoint_url = credentials["endpoint_url"]
             if not endpoint_url.endswith("/"):
                 endpoint_url += "/"
+            if not endpoint_url.endswith("v1/"):
+                endpoint_url += "v1/"
 
             # prepare the payload for a simple ping to the model
             data = {"model": model, "max_tokens": 5}