Fix Plastik bottom and right border
x and y are always relative to the parent, adding parent.width to
calculate the position doesn't make sense.
Original author meant just "x: parent.width-1"
But we may as well just use anchors. Programatically it comes out the
No more weird vertical lines in the KCM when view is slightly less than 2 previews wide.
Modded colour to hardcoded "red" for easier visualisation, checked it looked ok when set as a real deco.
Subscribers: plasma-devel, kwin, KWin
Differential Revision: https://phabricator.kde.org/D9776