Log Message:
Update to 20201211. From the changelog:

- reup: Delete, because retrying AUTH has been broken ever since TLS was
  added to authup.
- authup: Fix AUTH retries under TLS by inlining the retry logic.
- fixsmtpio: Fix process-management bugs in "Ensure STARTTLS resets all
  state by restarting qmail-smtpd."
- Manual pages: considerably improve clarity of authup(8) and
  fixsmtpio(8). Mention s6-ucspitlsd, a new UCSPI-TLS server
  implementation coming soon to s6-networking.