clear duplicate keybindings in the editor
@matthiasc
Submitted by Matthias Clasen Link to original bug (#752634)
Description
If I set multiple actions to use the same shortcut in the keybinding editor, only the last one works.
At a minimum, the editor should clean out all the other occurrences of this shortcut when setting it. It might be nicer to do as the control-center, and ask the user if he meant to override the existing shortcut.