Fix exception in blacklist feature

[TendTo]

Prerequisites

• I have read and understood the contributing guide.
• The commit message follows the conventional commits guidelines.
• Tested the changes locally with a real Telegram bot.
• I have updated the CHANGELOG.rst file with an overview of the changes made.

Description

Fix of the bug causing the following exception:

spotted.debug.log_manager - ERROR - Exception while handling an update:
Traceback (most recent call last):
  File "/usr/local/lib/python3.12/site-packages/telegram/ext/_application.py", line 1264, in process_update
    await coroutine
  File "/usr/local/lib/python3.12/site-packages/telegram/ext/_handlers/basehandler.py", line 157, in handle_update
    return await self.callback(update, context)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/spotted/handlers/spam_comment.py", line 20, in spam_comment_msg
    if message in info.message.text:
       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
TypeError: argument of type 'NoneType' is not iterable

Does this PR introduce a breaking change?

• Yes
• No

Python version you are using

3.11.8