textproc/libmrss: Update 0.19.2 => 0.19.4, take maintainership
Changelog:
https://github.com/bakulf/libmrss/blob/0.19.4/ChangeLog
Improve port:
- Upstream moved to GitHub.
- Replace CPPFLAGS and LDFLAGS with USES+=localbase.
- Replace PORTVERSION with DISTVERSION.
- Fix warnings from portclippy.
PR: 291664
Co-authored-by: Vladimir Druzenko <vvd@FreeBSD.org>