security/headscale: Update 0.27.0 => 0.27.1

Changelog:
https://github.com/juanfont/headscale/releases/tag/v0.27.1

• Replace PORTVERSION with DISTVERSION.
• Paramitrize USE_RC_SUBR.
• Reduce MKDIR calls.
• Use ${ETCDIR} instead of ${PREFIX}/etc/${PORTNAME}.

PR: 291006