Fix bot not replying to messages when it's not recognized as command

[TimJentzsch]

In the past, the bot used to reply to messages that it doesn't recognize as command. In case that the user intended to do something, it let them know that their message has been read, but that the command was wrong. In case that the user just commented on the post, it let them know that the they shouldn't.

Additionally, this would be a good opportunity to improve the reply message by including a note that the moderators have been pinged. This should reduce the number of users that keep commenting on posts.