Update Uploading_images_file.py

Uploading_images_file.py

@@ -56,4 +56,4 @@ def get_previous_message(user_id):
     if user_id in user_message_history and len(user_message_history[user_id]) > 0:
         # 返回最後一則訊息
         return user_message_history[user_id][-1]
-    return None
+    return 'No message!'