[InterNetNews/inn] e28a2a: scanspool: Improve the check for all-digit dirs

[Julien ÉLIE]

  Branch: refs/heads/main
  Home:   https://github.com/InterNetNews/inn
  Commit: e28a2a3d6acfa378b0bc4cd99b121ae29bdaf82b
      https://github.com/InterNetNews/inn/commit/e28a2a3d6acfa378b0bc4cd99b121ae29bdaf82b
  Author: Julien ÉLIE <Julien-Elie at users.noreply.github.com>
  Date:   2024-02-12 (Mon, 12 Feb 2024)

  Changed paths:
    M doc/pod/scanspool.pod
    M frontends/scanspool.in

  Log Message:
  -----------
  scanspool: Improve the check for all-digit dirs

Do not report a problem if the parent directory is not itself an active
newsgroup, or if it is and its high water mark has already exceeded the
number in the directory name.  Indeed, there's no longer any issue.