Radiance-GTK3: Fix CSS state pseudoclasses precedence
This fix is the same one that was applied to Ambiance
in Ubuntu Saucy:
http://bazaar.launchpad.net/~ubuntu-art-pkg/ubuntu-themes/trunk/revision/311
But this time for the Radiance theme. The launchpad
bug for Ambiance was:
https://bugs.launchpad.net/bugs/1211831.
Approved by PS Jenkins bot, Andrea Cimitan.