Remove repos with no language set for Repo.all_languages

When viewing your favorite languages in your profile, there is a check box with no value due to a language not being set on a Repo.  This removes Repos with no language set.

![screen shot 2013-10-17 at 3 38 31 pm](https://f.cloud.github.com/assets/625707/1356665/f83fe864-377c-11e3-956e-bb830b89a51c.png)