[InterNetNews/inn] 6ae01b: Remove references to collabra

[Julien ÉLIE]

  Branch: refs/heads/2.6
  Home:   https://github.com/InterNetNews/inn
  Commit: 6ae01b5a08f090d018ed5dcbea1891f322ea2939
      https://github.com/InterNetNews/inn/commit/6ae01b5a08f090d018ed5dcbea1891f322ea2939
  Author: Julien ÉLIE <Julien-Elie at users.noreply.github.com>
  Date:   2022-02-05 (Sat, 05 Feb 2022)

  Changed paths:
    M doc/pod/newsfeeds.pod
    M samples/newsfeeds.in

  Log Message:
  -----------
  Remove references to collabra

Netscape Collabra Server was an NNTP server known to create control messages
with the collabra-internal distribution when newsgroups were created or
removed locally.

It is no longer in use.  Remove the references to it in newsfeeds.