Delete sleeping requirement for non-empty roles

The kernel contains bits of code that is commented because it has been waiting for role policy editing to be implemented. This is present now, so the code should be uncommented and tested.

API team decided this is not worth it - so much code has been written not taking this into account, and it will require big rewrites without a big benefit, so it's better to axe the sleeping code.

Example: https://github.com/ezsystems/ezpublish-kernel/blame/47fb0c14beadffedcdc03b4f9706efff5e8c184f/eZ/Publish/Core/Repository/RoleService.php#L536

Role policy editing: https://jira.ez.no/browse/EZP-24711 and https://jira.ez.no/browse/EZP-24713