which makes modal dialogs (which are most of them) place correctly
under wayland. Modeless ones are still uselessly shoved far to the
left, but this makes things near usable and gives the same "graying
into the bg" effect for the main window as other gtk apps

Change-Id: If1486feb7631c5a0c2aa6efac3a6b9dd1b215daf
Reviewed-on: https://gerrit.libreoffice.org/20699Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>
(cherry picked from commit 8d582298)
Reviewed-on: https://gerrit.libreoffice.org/20700