Remove visual noise from winaccessibility

Change-Id: If8ac2543e3dca393e14380a85547cafbb68ab8c6
Reviewed-on: https://gerrit.libreoffice.org/8340
Tested-by: LibreOffice gerrit bot <gerrit@libreoffice.org>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>