This allows opening files with the xlsm and xltm extensions
(Excel macro-enabled workbooks and templates).

Change-Id: I9282f83ff15108a703b98f1752eeee94a2f174c1
Reviewed-on: https://gerrit.libreoffice.org/50514Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Thorsten Behrens <Thorsten.Behrens@CIB.de>