Bug 15600: System preferences broken toolbar looks broken

Bug 15600: System preferences broken toolbar looks broken

This patch reverts some deletions made to staff-global.css in Bug 11559.
The deletions broke the appearance of the floating toolbar in system
preferences.

To test, apply the patch and clear your browser cache if necessary.

- Go to Administration -> System preferences and view a tab with enough
  content to allow you to scroll and test the appearance of the floating
  toolbar. Confirm that it looks correct.
- Open the advanced cataloging editor and confirm that its toolbar looks
  correct.
- Open the normal cataloging editor and confirm that the floating
  toolbar looks correct and works correctly.

Signed-off-by: Hector Castro <hector.hecaxmmx@gmail.com>
Works as advertised. Tollbar looks correct

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Brendan Gallagher brendan@bywatersolutions.com