Log Message:
Update to the latest upstream git. From the changelog:

- Set QMAILPPID for filters to know grandparent PID. Filters can log
  this information to help sysadmins correlate rejections with
  qmail-smtpd sessions.
- qmail-qfilter.1: Fix typo regarding file descriptor 5, and some
  spellings and phrasings.
- README: Drop the stanza about setting TMPDIR, no longer relevant.
- Relicense from gnu-gpl-v2 to unlicense.