Private customer registered on frontend is not visible in back-office.

Steps:

1. On frontend as guest go to /register/private.
2. Fill mandatory data.
3. Register.
4. Log in to back-office.
5. Go to Users / Shop users / Private customers.
6. Verify if new user was created.

Actual result: User is not visible in back-office. On frontend registration ends with confirmation message "Thank you for your registration. In a few minutes you will receive a confirmation email.".
Expected result: User is available in back-office.