Remove visual noise from extensions

Change-Id: I0397d0d0e5343b7ed192a790664b068ac6955bd3
Reviewed-on: https://gerrit.libreoffice.org/8259
Tested-by: Caolán McNamara <caolanm@redhat.com>
Reviewed-by: Caolán McNamara <caolanm@redhat.com>