fix invalid reference

app.py

@@ -254,7 +254,7 @@ def fetch_data() -> None:
     This function fetches the data from the source and target datasets and updates the global variables.
     """
 
-    print(f"Starting to fetch data: {datetime.datetime.now()}")
+    print(f"Starting to fetch data: {datetime.now()}")
 
     global source_dataset, target_dataset, user_ids_annotations, annotated, remaining, percentage_completed, top_dataframe
     source_dataset, target_dataset = obtain_source_target_datasets()
@@ -267,7 +267,7 @@ def fetch_data() -> None:
     )
 
     # Print the current date and time
-    print(f"Data fetched: {datetime.datetime.now()}")
+    print(f"Data fetched: {datetime.now()}")
 
 
 def get_top(N = 10) -> pd.DataFrame: