Bug 1086427 - Do not use JSON.load() with untrusted JSON

* see https://www.ruby-lang.org/en/news/2013/02/22/json-dos-cve-2013-0269/
Bug 1086427 - JSON.load() allowed empty JSON files
Merge pull request #5265 from jwhonce/bug/1086427

Merged by openshift-bot