Scheduled maintenance [Jan 15, 00:00 CET]

We'll bring down the central authentication system for upgrade and
maintenance. The operation will start on Sat, 15 Jan 2022 at 00:00 CET
and is expected to complete within 1h (around 01:00 CET).

Creating *new* Single Sign-On accounts or sessions won't be possible
while the maintenance is in progress. Affected services include our
gerrit, Redmine, AskLibO, and Nextcloud instances (Weblate and Bugzilla
are OTOH not affected). Existing sessions for these services will
remain valid through the maintenance, so we recommend that folks log in
or refresh their session before 00:00 CET in order to limit disruption.