Code review comment for lp:~l-admin-3/gala/workspace-switcher-background-setting

Ok, I will create a new branch later.

But I don't understand what the advantage of making some checks before trying to load the background should be.
Theese checks would be executed on every start up. My solution would only be executed if the choosen wallpaper isn't existent/readable/broken. So the startup would be fast like ever and would only be a small bit slower if the wallpaper isn't useable.