security/kanidm: Upgrade to 1.8.0

• Add kanidmd_config parameter to rc script.
• Fix server flavor.
• Fix missing Web UI.
• Improve pkg-descr (also fixes warning in portlint).

ChangeLogs:

• https://github.com/kanidm/kanidm/releases/tag/v1.7.4
• https://github.com/kanidm/kanidm/releases/tag/v1.8.0

PR: 290372
Reported by: brad@facefault.org
Approved by: bofh@freebsd.org (maintainer-timeout)