[Mimedefang] md_graphdefang_log() must be called "in message context"?

[Gary Funck]

I tried to add some MDLOG entries in filter_relay()
and filter_recipient(), but md_graphdefang_log() complained
that it wasn't called inside a message context, which seems
to indicate that the filter() action is active?

This check seems overly restrictive.  I notice that
that md_graphdefang_log() wants to record $Subject and
$MsgID into log entry, so probably filter_relay() is out,
but in filter_recipient(), I already have executed
read_commands_file() before calling md_graphdefang_log(),
so I presume that both variables are valid?  And, a call from
filter_relay() would be OK, if the code just checked to see
where $MsgID and $Subject are defined, and if not, md_graphdefang_log()
could use either a null string or a question mark for their value.

Thoughts?