Privacy in communication preferences does not update when blanked out.

The privacy parameters of the contacts Communication preferences is not updated when they are cleared.

Reproduction:

1 - Create an Individual
2 - Mark all 3 (do not phone, do not email, do not mail).
3 - Save Individual.
4 - Edit individual.
5 - Unmark all checkboxes of Privacy and save.
6 - Values are still 1 for crm_contact (do_not_phone, do_not_email, do_not_mail).