Log Message:
Update to 20170720. pkgsrc changes:

- Remove qmail-qfilter-*-queue shell scripts, which would conflict with
  the C programs of the same name included in mail/qmail 1.03nb29 with
  the "qmail-rejectutils" option (enabled by default).

- Bump mail/qmail dependency to 1.03nb29.

- Shorten and improve MESSAGE.