Fixed errors in the message throttle code

I was getting errors when I attempted to `cabal install`. After
changing the following I was able to install successfully.

* Replaced → with ->
* Replaced ← with <-
* Fixed indentation in case statement
Merge pull request #9 from cameronbwhite/master

Fixed errors in the message throttle code
Oh interesting, this hasn't been an issue in the past. I'll keep it in mind, thanks.