Bug 924793 - Make select box align with other buttons in settings app

Fix the style of `fake-select` class and make it align with `ul li button`.

This problem only happens on v.1.1.0hd but not on master or v1.2. And it's hard to find which patch had this problem fixed.

[Link to Bug 924793 - [B2G][Helix][settings][chenhoulai] The drop-down box do not align with the other buttons of the same page in settings app.](https://bugzilla.mozilla.org/show_bug.cgi?id=924793)