non-activated users aren't deleted from the DB after 24 hours

How to reproduce:

1. sign up a user
2. don't click on activation link in e-mail notification in 24 hours

As a result, user is still shown in the DB with enabled=0 in jc_user_details table.
It is expected that in case user didn't follow the activation link from email notificationin 24 hours, he should be deleted fron the DB

Note, that it works as expected on the deploy instance.