Fix problem with window unmaximization

A mismerge of the Metacity commit "4943d79d Prevent window self-maximisation"
caused the window's user set size and position to be saved *before*
actually resizing the window to the unmaximized position rather than after.

This meant that after unmaximization the window was in an inconsistent
state and anything that caused a resize to be queued (like a change in
window properties by the application) would cause it to pop back to
the maximized size and position.

https://bugzilla.gnome.org/show_bug.cgi?id=621413