security/amavisd-new: Fix installing from official pkg repo

Remove LHA from from the default options. This change makes it possible
to use amavis-new from the official packages repo again. This hasn't
been possible since archivers/lha packages may not be distributed, thus
trying to install amavisd-new failed with the following error message

pkg: amavisd-new has a missing dependency: lha

PR: 265240
Reported by: James B. Byrne <byrnejb@harte-lyne.ca>