Bug#690017: gnome-session craps out when cups not available.

[Daniel Kahn Gillmor <dkg@fifthhorseman.net>]

Control: retitle 690017 "Oh no! Something has gone wrong" when /var/run/cups/cups.sock is not accessible at login

I wouldn't be surprised if #690017 and #687978 are caused by the same
underlying problem.

           --dkg