Properly detect InnoDB setups which are "NO" or "DISABLED"
Summary: See D2160, http://dev.mysql.com/doc/refman/5.5/en/show-engines.html
Test Plan: Ran setup.
Reviewers: vrana, btrahan
Reviewed By: vrana
CC: aran
Differential Revision: https://secure.phabricator.com/D2219