During ODF import using API for CustomShapes Outliners and
VirtualDevioces get created and not destroyed due to referencing.
This makes the ressources blow up, even under 64bit windows.
Also see tdf#93994 where this was already fixed on page base,
but this is not sufficient for this case.

Change-Id: If9b37d341fcfa4e65485c54054d47964ee2fff5f
Reviewed-on: https://gerrit.libreoffice.org/24305Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Armin Le Grand <Armin.Le.Grand@cib.de>