net/wireguard-tools: Set maintainer

Improve port:

• Replace PORTVERSION with DISTVERSION.
• Remove MAKE_ENV+=MANDIR="${PREFIX}/share/man" - it's default value.
• Fix warnings from portclippy.
• Improve indents.
• Replace ".if ${PORT_OPTIONS:MWGQUICK}" with "WGQUICK_VARS= USE_RC_SUBR=wireguard_wgquick".
• Add strip bin/wg.

PR: 292620
Approved by: Juhani Krekelä <juhani@krekela.fi> (new maintainer)