as MsgBox used to do

Change-Id: I03d459b8c18f60a19ea5b0034a8d98f6aa4f5ce4
Reviewed-on: https://gerrit.libreoffice.org/63117
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>