[InterNetNews/inn] 5a365e: Several bug fixes in CNFS storage token handling

[Julien ÉLIE]

  Branch: refs/heads/2.7
  Home:   https://github.com/InterNetNews/inn
  Commit: 5a365e68d8c3a51ae5a65ecbc7fad98a0b467cfc
      https://github.com/InterNetNews/inn/commit/5a365e68d8c3a51ae5a65ecbc7fad98a0b467cfc
  Author: Julien ÉLIE <Julien-Elie at users.noreply.github.com>
  Date:   2022-12-24 (Sat, 24 Dec 2022)

  Changed paths:
    M doc/pod/news.pod
    M storage/cnfs/cnfs.c

  Log Message:
  -----------
  Several bug fixes in CNFS storage token handling

Fixed 3 bugs reported by Kamil Jońca on CNFS:

- a duplicate entry returned by makehistory on fully wrapped cyclic buffers
(the first article of the cyclic buffer appeared twice in the output);

- an untimely removal from history of the first article of a fully wrapped
cyclic buffer (expire wrongly thought the storage token of the first article
was no longer existing after a wrap);

- an off-by-one cycle number for the first article of the previous cycle
number of a cyclic buffer containing articles from two different cycle numbers
(makehistory returned the current cycle number for it instead of the previous
one).

close #248