Patch the JSONLint external to be compatible with PHP 5.2

Summary: The JSONLint external utilizes the shorthand ternary (?:) syntax, which is only available from PHP 5.3. Expand the shorthand ternary form into ordinary ternary form to ensure compatibility with PHP 5.2. Depends on D10433.

Test Plan: Not sure how...

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D10435