KDED: respond to output being completely removed
Summary:
On Wayland outputs are not merely disconnected, they are completely removed from
the config. In order to apply config that matches the new configuration of available
outputs we need to listen to output removal, not just change in the connected
property.
Reviewers: sebas, davidedmundson
Reviewed By: sebas
Subscribers: plasma-devel
Tags: Plasma
Differential Revision: https://phabricator.kde.org/D9903