mail/msmtp: remove ca_root_nss dep
msmtp 1.8.2[0] onwards selects the system trust store by
default when TLS is enabled, so ca_root_nss is no longer
necessary.
Other minor changes:
- PORTVERSION -> DISTVERSION
- enable test suite
- simplify Makefile style
[0] https://marlam.de/msmtp/news/msmtp-1-8-2/
Reviewed by: novel
Approved by: lwhsu (mentor)
Signed-off-by: Siva Mahadevan <siva@FreeBSD.org>
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D54720