[bug] problem when setting the drawer tile

[Idan Sofer <sofer ibm net>]

I noticed this problem on Gnome 0.99.8.1.

When setting the drawer tile in global properities, if in the icon choser
you chose a tile but click cancel in the chooser, and then in the global
properities you click apply, the new tile will be accepted even if it was
not applied in the icon chooser