when calling methods that take a const&

Change-Id: Idf45dfd9fea0de6fae0b1f89550f2f7fc302aa15
Reviewed-on: https://gerrit.libreoffice.org/50970Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>