Make undelete button hover text lighter

Hover text for undelete currently looks like this.

![current hover](http://cl.ly/image/3a1b2E1u3V1Z/Screen%20Shot%202013-04-18%20at%2011.00.11%20AM.png)

This makes it look like this.

![patch hover](http://cl.ly/image/0m2Q401m420j/Screen%20Shot%202013-04-18%20at%2011.13.47%20AM.png)