This is required since RGPD requires this field value to be stored in database.

The way RGPD feature works does not change, it still disabled by default and
can be enabled from settings.

Field won't never display in form when feature is disabled, but still show in
the admin. When enabled the field shows in form and is required to submit job
application.

This change involve a new migration which should be transparent from
integration with older version.