Update app.py

app.py

@@ -198,7 +198,7 @@ def demo():
         retriever=vector_db.as_retriever()
         memory = ConversationBufferMemory(memory_key="chat_history", output_key='answer', return_messages=True)
         qa_chain = ConversationalRetrievalChain.from_llm(llm,retriever=retriever,chain_type="stuff", 
-                                                         memory=memory,return_source_documents=True,verbose=False,)
+                                                         memory=memory,return_source_documents=True,verbose=False)
         # Chatbot events
         msg.submit(conversation, \
             inputs=[qa_chain, msg, chatbot], \