[Galene] Heads up: slight change to the format of tokens

[Juliusz Chroboczek <jch@irif.fr>]

Hi,

I've just implemented the commands /shutup and /unshutup, which make it
possible to prevent a client from sending chat messages.  It's the second
time that this 

Sending messages is now governed by an explicit permission (the right to
send messages used to be implicitly granted).  This means that:

  - if you're using the "new" configuration format, you should use
    "message" instead of "observe" if you wish to grant a user the
    permission to send messages but not to participate with video and
    audio; "observe" no longer has the right to send chat messages;
  - if you're using the old (0.8) configuration format, nothing changes;
  - if you're using galene-ldap, you need to upgrade to a version dated
    2024-05-08 or later;
  - if you're generating stateless tokens in your own software, you need
    to add the "message" value to the "permissions" field in addition to
    the "present" value.

As far as stateful tokens are concerned, Galene master transparently adds
the "message" permission when loading tokens from disk; the effect is that
it's not currently possible to generate a token without the "message"
permission (or, more accurately, it's possible to generate such a token,
but the "message" permission will be added as soon as the token is
reloaded from disk).  I intend to remove this hack sometime in late 2024.

-- Juliusz