Disable tracking protection UI in FF67-esr

Some of its parts are already live and well in Nightly (such as the Tracking Protection switch in the hamburger menu). This makes it particularly devastating since more users may be tempted to enable it thereby harming their fingerprinting.

https://bugzilla.mozilla.org/show_bug.cgi?id=1461743

https://www.ghacks.net/2018/06/10/mozilla-plans-to-push-tracking-protection-in-firefox/