Log Message:
mutt: Update to version 1.13.4

This release fixes a potential memory corruption issue when sync'ing imap
mailboxes.  It also improves the speed of opening mailboxes with large threads
(when sorting by thread).  Lastly, it changes the default of $ssl_force_tls
back to unset.

1.13.4 (2020-02-15):
  ! Bug fix release.
  ! $ssl_force_tls reverted to default unset.  Defaulting this set was
    overly optimistic, and caused breakage.