Update app.py

app.py

@@ -51,7 +51,7 @@ hf_llm = HuggingFaceEndpoint(
     max_new_tokens=512
 )
 
-def source_question_answer(query:str,vectorstore:Chroma=chroma_db,llm:HuggingFaceHub=hf_llm):
+def source_question_answer(query:str,vectorstore:Chroma=chroma_db,llm:HuggingFaceEndpoint=hf_llm):
   """
   Return answer to the query
   """