[InterNetNews/inn] 080646: Fix an out-of-bounds access

[Julien ÉLIE]

  Branch: refs/heads/main
  Home:   https://github.com/InterNetNews/inn
  Commit: 080646a901163cf1bcf7a86a7e127a9800f1feef
      https://github.com/InterNetNews/inn/commit/080646a901163cf1bcf7a86a7e127a9800f1feef
  Author: Julien ÉLIE <Julien-Elie at users.noreply.github.com>
  Date:   2023-11-02 (Thu, 02 Nov 2023)

  Changed paths:
    M lib/headers.c

  Log Message:
  -----------
  Fix an out-of-bounds access

Issue seen on CheriBSD running on a Morello board
(core dump when running the test suite).