Update app.py

app.py

@@ -10,7 +10,7 @@ ChurnData =  os.environ.get('Churn_Data')
 ChurnData2 =  os.environ.get('Churn_Data2')
 
 #read data
-from llama_index import VectorStoreIndex, SimpleDirectoryReader, SummaryIndex, download_loader
+from llama_index.core import VectorStoreIndex, SimpleDirectoryReader, SummaryIndex, download_loader
 DataReader = download_loader(Data_Read)
 loader = DataReader()