Fixed huggingfacehub_api_token hadning in HuggingFaceEndpoint (#4335)

Reported here:
https://github.com/hwchase17/langchain/issues/4334

---------

Co-authored-by: Pawel Faron <ext-pawel.faron@vaisala.com>

langchain/llms/huggingface_endpoint.py

@@ -73,6 +73,7 @@ class HuggingFaceEndpoint(LLM):
                 "Could not import huggingface_hub python package. "
                 "Please install it with `pip install huggingface_hub`."
             )
+        values["huggingfacehub_api_token"] = huggingfacehub_api_token
         return values
 
     @property