net/krill: Update to 0.12.1

ChangeLog: https://www.nlnetlabs.nl/news/2023/Jan/17/krill.0.12.1-released/

Firstly, this release fixes
CVE-2023-0158

Secondly, locking was added in this release to ensure that updates
to the repository content are always applied sequentially. This
fixes a concurrency issue introduced in Krill 0.12.0 that could
result in rejecting an update from a publishing CA.

PR: 269050
Reported by: jaap@NLnetLabs.nl (maintainer)
MFH: 2023Q1 (security fix)
Security: CVE-2023-0158

(cherry picked from commit bb104a8ee1912bb409408601e479658e5c9f0f60)