visad-list-digest working again

Thanks to one subscriber for pointing out that visad-list-digest
has not been working. visad-list is pretty busy, but the messages
have not been digested to visad-list-digest for quite a while.
Sorry about that. The SSEC sys admins found a bad line in one of
their email management files that was causing the problem. It
should be fixed now.

If in the future anyone notices a lack of messages on
visad-list-digest for a week or more, please let me know.