Remove thumbnail generation
https://redmine.teklia.com/issues/6067
Requires arkindex/workers/thumbnails#2 (closed)
The Process.generate_thumbnails field must be removed, as thumbnail generation will be moved to a worker instead.
The That part has been done in #1722 (closed)thumbnail_put_url attribute on elements should now be returned for corpus admins, regardless of Ponos authentication, and the help text should be updated to reflect that.
Edited by Erwan Rouchet