Weaken the guidance recommending that installs enable "STRICT_ALL_TABLES"

Summary: Ref T13404. Enabling "STRICT_ALL_TABLES" is good, but if you don't want to bother it doesn't matter too much. All upstream development has been on "STRICT_ALL_TABLES" for a long time.

Test Plan: {F6847839}

Maniphest Tasks: T13404

Differential Revision: https://secure.phabricator.com/D20790