fdo#54514 fix Tango icon names

Change-Id: I4144e94cc3c1a3e068e0f9bca4b73e5c63a9274a
Reviewed-on: https://gerrit.libreoffice.org/7223
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>