Update app.py

app.py

@@ -18,7 +18,7 @@ from tavily import TavilyClient
 import pprint
 
 from langchain.chains import LLMChain, RetrievalQA
-from langchain.chat_models import ChatOpenAI
+from langchain_openai import ChatOpenAI
 from langchain.document_loaders import PyPDFLoader, WebBaseLoader, UnstructuredWordDocumentLoader, DirectoryLoader
 from langchain.document_loaders.blob_loaders.youtube_audio import YoutubeAudioLoader
 from langchain.document_loaders.generic import GenericLoader