revert changes to llm

Author: Ziqun Ye

ads/llm/langchain/plugins/llm_gen_ai.py

@@ -64,7 +64,7 @@ def _identifying_params(self) -> Dict[str, Any]:
         return {
             **{
                 "model": self.model,
-                "task": self.task.value,
+                "task": self.task,
                 "client_kwargs": self.client_kwargs,
                 "endpoint_kwargs": self.endpoint_kwargs,
             },