Update app.py

app.py

@@ -6,7 +6,7 @@ from huggingface_hub import login
 from langchain_text_splitters import RecursiveCharacterTextSplitter
 from langchain_community.embeddings import SentenceTransformerEmbeddings
 from langchain_community.vectorstores import FAISS
-from langchain.chains import RetrievalQA
+from langchain_classic.chains import RetrievalQA
 from langchain_core.prompts import PromptTemplate
 from langchain_community.llms import HuggingFacePipeline
 from langchain_community.document_loaders.csv_loader import CSVLoader