Update app.py

app.py

@@ -3,9 +3,8 @@ from langchain_community.document_loaders.pdf import PyPDFDirectoryLoader
 from langchain.text_splitter import CharacterTextSplitter
 from langchain_community.embeddings import HuggingFaceInstructEmbeddings
 from langchain_community.vectorstores import FAISS
-from langchain.chains import ConversationalRetrievalChain
+from langchain.chains import RetrievalQA
 from langchain_community.llms import HuggingFaceHub
-from langchain.memory import ConversationBufferMemory
 
 def make_vectorstore(embeddings):