Ignore empty value when validating user IDs

bot/telegram_bot.py

@@ -632,6 +632,8 @@ class ChatGPTTelegramBot:
         if self.is_group_chat(update):
             admin_user_ids = self.config['admin_user_ids'].split(',')
             for user in itertools.chain(allowed_user_ids, admin_user_ids):
+                if not user.strip():
+                    continue
                 if await self.is_user_in_group(update, context, user):
                     logging.info(f'{user} is a member. Allowing group chat message...')
                     return True