Update CHANGES.

CHANGES

+Galène 0.4.1 (unreleased):
+
+  * Create a new file data/config.json with global configuration.
+  * Remove data/passwd and the -redirect option with entries in config.json;
+    these are incompatible changes.
+  * Change the group URL from /group/name to /group/name/, which allows
+    using relative links.  The old URL is redirected to the new one.
+  * Extend the protocol with the ability to consult the group status before
+    joining; this allows using the group's displayName before the user has
+    logged in, and will be required for new authorisation schemes.
+  * Allow scrolling of the login dialog, useful on small devices.
+  * Fixed a typo that prevented the group name from being displayed.
+
 5 September 2021: Galène 0.4
 
   * Implemented simulcast.