hook_civicrm_post empty values on disable/enable field through contact relationship tab.

1. Set up an extension with a post hook that dumps the contents of objectRef.
2. Click on a contact.
3. Click on the relationship tab.
4. Next to a relationship click 'enable' or 'disable' NOT 'edit'
5. Observe in the objectRef log made by your extension that relationship_type_id, contact_id_a, contact_id_b, and is_active are all empty.