Log Message:
mutt: Update to version 2.1.5

This is a bug-fix release.  Fixes include:
* a regression with SMTP authentication, where Mutt would force authentication
  when a server advertised AUTH.
* a possible SMTP server response overread, although I don't believe there is
  a security issue here.
* a SEGV bug on NetBSD when trying to use low level terminfo routines. Because
  of this fix, Mutt now looks for the term.h header before enabling these
  routines.  Packagers should ensure this header is present in the build
  dependencies.
* format=flowed text is space-unstuffed before piping to
  $send_multipart_alternative_filter