Log Message:
msmtp: Update mail/msmtp to 1.8.0

pkgsrc changes:
- Update HOMEPAGE and MASTER_SITES
- Remove inet6 option (it was actually a no-op)
- Adjust libidn dependency to libidn2 per 1.8.0 change
- Cleanup the options.mk a bit: no need to add pkg-config to USE_TOOLS, it was
  already needed as tool and remove all --with-*-prefix= because pkg-config is
  used for that

Changes:
Version 1.8.0:
- A minimal SMTP server called msmtpd was added that listens on the local host
  and pipes mails to msmtp (or another program). It is intended to be used with
  system services that cannot be configured to call msmtp directly. You can
  disable it with the configure option --without-msmtpd.
- Using OpenSSL is discouraged and may not be supported in the future. Please
  use GnuTLS instead. The reasons are explained here:
  https://marlam.de/msmtp/news/openssl-discouraged/
- As using GNU SASL is most likely unnecessary, it is disabled by default now.
  Since everything uses TLS nowadays and thus can use PLAIN authentication, you
  really only need it for GSSAPI.
- If your system requires a library for IDN support, libidn2 is now used instead
  of the older libidn.
- The CRAM-MD5 authentication method is marked as obsolete / insecure and will
  not be chosen automatically anymore.
- The passwordeval command does not require the password to be terminated by a
  new line character anymore.
- The new logfile_time_format command allows to customize log file time stamps.
- Builtin default port numbers are now used instead of consulting /etc/services.
- Support for DJGPP and for systems lacking vasprintf(), mkstemp(), or tmpfile()
  is removed.

Version 1.6.8:
- Add --source-ip option and source_ip command to bind the outgoing connection
  to a specific source IP address.
- Enable SNI for TLS

Version 1.6.7:
- Add support for ~/.config/msmtp/config as configuration file
- Add network timeout handling on Windows
- Fix command line handling of SHA256 TLS fingerprints
- Fix SIGPIPE handling (affects at least Mac OS X)
- Add french translation, and update german translation