Mattermost broken after automatic update

After an automatic update, Mattermost no longer starts. The issue has been identified; the solution requires relocating the installation. This may take some time.

Mattermost is now running on a different server as gitlab, which was a lot of work to figure out, but all should be well now. For some people it may have been longer before everything worked, due to dns caching of the hostname mattermost.science.ru.nl to the wrong address.