[openbox] A problem with a gtk window using CSD

[Rafał Mużyło]

This dates back to 3.10 release, but I initially thought it's a gtk bug.
However, today I've retested it with icewm and the most annoying part of
the problem didn't trigger.

So, for example, run recent devhelp. It uses GtkApplicationWindow,
which more or less means CSD. Now, double click its menubar to maximize
it. Next double click should restore it, but in openbox, for whatever
the reason, it doesn't - on a slow hardware you can see, that initially
window is attempting to be restored, but it's immediately maximized (or
perhaps even made larger than the desktop) again.

Also, even in icewm after it's restored in size, the position isn't
preserved, but that could be just a gtk bug.