Update app.py

app.py

@@ -5,8 +5,7 @@ from langchain_huggingface import HuggingFaceEmbeddings, HuggingFaceEndpoint
 from langchain_community.llms import HuggingFaceHub
 from langchain.chains import ConversationalRetrievalChain
 from langchain.text_splitter import RecursiveCharacterTextSplitter
-from langchain.memory   
- import ConversationBufferMemory
+from langchain.memory import ConversationBufferMemory
 from langchain_community.document_loaders   
  import PyPDFLoader
 import os