Make rendered table of contents private in Phriction

Summary: Oops, I missed this -- when properties are protected, Lisk assumes they database properties which should be stored and read from the database. To make Lisk ignore a property, make it private.

Test Plan:
Should fix this:

{F990757}

Reviewers: chad

Reviewed By: chad

Differential Revision: https://secure.phabricator.com/D14538