don't scale highlighted window in present windows during de/activation

BUG: 283481
it's even worse, since it interferes with generally upscaled windows
(keeps them big, applies false transition and causes a final snapback)
and windata->highlight doesn't end at zero, so the entire screen is
still a little scaled when the effect ends (and snaps down afterwards)

now it snaps down when starting the leave what is better in general
and the only usable solution for upscaled windows.
some day presentwindows might be derived from the yet-to-add
animationeffect class ;-)