Bug fixes

Following the latest DSB API changes, JSON validation is more strict.
Make sure empty classification items are not exported in the JSON file.

- Fix chrome delete config in edit variables of less compiler,
- Fix broken submit on less config.

The first alpha release.

#3005678
After updating Drupal Core to 8.6.x the user export was not working anymore. This should now work again.
See also: #2936397

#3005678
After updating Drupal Core to 8.6.x the user export was not working anymore. This should now work again.
See also: #2936397