Remove visual noise from xmloff

Change-Id: I205d4e555f5b88654a90007eb7ac05bc7b00a904
Reviewed-on: https://gerrit.libreoffice.org/8346
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>