[H-ADMIN] Pycon email lists disabled

[Russell Stuart]

I've disabled the pycon and pycon-volunteers lists, hopefully.

For future reference for each list I:

  - Set it into emergency moderation.
  - Reject every moderated post by saying the list is closed.
  - Ban all email addresses from subscribing.
  - Discard all emails from non-members.
  - Added a note in the short description saying the list is closed.