Update app.py

app.py

@@ -85,7 +85,7 @@ qa_prompt = ChatPromptTemplate.from_messages(
     [
         ("system", qa_system_prompt),
         MessagesPlaceholder("chat_history"),
-        ("user", "{input}"),
+        ("human", "{input}"),
     ]
 )
 question_answer_chain = create_stuff_documents_chain(llm, qa_prompt)