This is still not enough to make PowerPoint happy with the test file.

Change-Id: Icadcb640b44100ffb3482de57723576e4d843e7a
Reviewed-on: https://gerrit.libreoffice.org/41977Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Jan Holesovsky <kendy@collabora.com>