These are needed to invoke the ODF validator with custom ODF schemas.

Change-Id: I231b5d8a8573e9ac6171a331362a31aceae08d80
Reviewed-on: https://gerrit.libreoffice.org/56399
Tested-by: Jenkins
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>