mail/mutt: Update to 2.0.4

A bugfix release.

And while here, also reformat Makefile according to portfmt and portclippy

PR: 252295
Submitted by: Derek Schrock <dereks@lifeofadishwasher.com> (maintainer)
Reviewed by: osa (mentor)
Approved by: osa (mentor)
Differential Revision: https://reviews.freebsd.org/D27951