Remove visual noise from writerfilter

Change-Id: I2470e26f1b0a7c3b28fbc0ec44170565f250fc40
Reviewed-on: https://gerrit.libreoffice.org/8342
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>