Fixed Bug 812603: Contacts list alphabetical index on the right overlaps with search bar

Fixed Bug 812603. The UI now looks as depicted in the screenshot.
https://bugzilla.mozilla.org/show_bug.cgi?id=812603
![Screenshot from 2013-02-21 19:35:00](https://f.cloud.github.com/assets/1485255/180402/c1615be2-7c2f-11e2-8a1d-74983a9c541c.png)