unity-control-center doesn't change background

[Michael Blennerhassett]

- Go to control-center -> appearance
- Change the background
Expect that the background changes

What happens is the background doesn't change
(log out/in to get the background to change)

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: unity-control-center 15.04.0+15.04.20141217-0ubuntu2
ProcVersionSignature: Ubuntu 3.18.0-12.13-generic 3.18.4
Uname: Linux 3.18.0-12-generic x86_64
ApportVersion: 2.15.1-0ubuntu4
Architecture: amd64
CurrentDesktop: Unity
Date: Sun Feb 1 17:58:16 2015
InstallationDate: Installed on 2015-01-31 (0 days ago)
InstallationMedia: Ubuntu 14.10 "Utopic Unicorn" - Release amd64 (20141022.1)
SourcePackage: unity-control-center
UpgradeStatus: Upgraded to vivid on 2015-01-31 (0 days ago)
usr_lib_unity-control-center: deja-dup 32.0-0ubuntu2