Log Message:
mate-control-center: update to 1.22.1

### mate-control-center 1.22.1

  * tx: sync with transifex
  * default-applications: Improve UI accessibility
  * Use keyboard device icon like in other hardware devices
  * control-center: Fix memory leak
  * Use GtkSeparatorMenuItem in Apparence preview
  * Remove dead store detected by clang
  * Use icons provided by themes and remove not used icons
  * help: update copyright