This has been a problem since 0.7.4 however it went unnoticed because it was fairly uncommon to send messages that start with a /. This also fixes #2588, it's not that the history entry wasn't added but that when closing the chat I forgot to clear the current history entry. (closing the chat maybe should be refactored into a function) I'm not sure if we should actually fix it like this though, maybe it should be fixed as part of #2568? Could implement different types of history entries ...