Impossible to configure printers from GNOME control center

Originally created by @sajolida on #7636 (Redmine)

In Tails 1.1~rc1 when choosing Applications → System Tools → Preferences
→ System Settings → Printers, the window is greyed out and it is not
possible to add a new printer.

Feature Branch: bugfix/7636-printers-configuration

Related issues

Related to #8443 (closed)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information