net/krill: add new port

Krill is a free, open source RPKI Certificate Authority that lets you
run delegated RPKI under one or multiple Regional Internet Registries
(RIRs). Through its built-in publication server, Krill can publish Route
Origin Authorisations (ROAs) on your own servers or with a third party.

WWW: https://www.nlnetlabs.nl/projects/rpki/krill/

PR: 257355