Force pushing a commit to a theme repository used to break the updater,
because the system was not able to count the commits behind the old and
new version. This operation failed because a force push deleted the old
commits.
The user was prompted with a simple "500 server error" message.
Themes marked for auto update will be automatically updated when
Discourse is updated. This is triggered by discourse_docker or
docker_manager running Rake task 'themes:update'.
Allowing the editing of remote themes has been something Discourse has advised against for some time. This commit removes the ability to edit or upload files to remote themes from Admin > Customize to enforce the recommended practice.