Fix admin auto complete css

See before/after screenshots. Currently, autocomplete results are returned as white text making them invisible.
![screenshot from 2013-05-28 10 00 45](https://f.cloud.github.com/assets/540762/573267/0f2a884e-c7ad-11e2-8bae-66b0a140d874.png)
![screenshot from 2013-05-28 11 38 58](https://f.cloud.github.com/assets/540762/573269/11845192-c7ad-11e2-9a41-811b2336feb3.png)