No bug - Clean up in-progress shortcut key conditional

Nothing exciting, I just noticed this in passing while doing other shortcut work for bug  [1030686](https://bugzilla.mozilla.org/show_bug.cgi?id=1030686). It wasn't really within the scope of that work, so I thought I'd fix it separately.

nb. Toggle in-progress jobs isn't working currently per [1106646](https://bugzilla.mozilla.org/show_bug.cgi?id=1106646) due to other reasons.

Tested on Windows:
FF Release **33.1.1**
Chrome Latest Release **39.0.2171.71 m**

Adding @wlach for review.