Remove the MESSAGE_TAGS from the default projects. The idea was to map the MESSAGE_TAGS to Bootstrap css classes. However, this breaks the default Django admin behavior css, since it does not show error icons any more.

Also see the discussion on slack.

Django error messages do not show as error messages anymore in the admin (They're green and have the wrong icon). The other solution would be to extend the Admin CSS with a error icon for the '.danger' class. I don't have any preference.