Git commits in Moodle 3.6.x by Olivier Piton

commit 24eae720fa9435a135a44b271b4935379163a2c3
Author: Olivier Piton <olivier@cblue.be>
Date:   Thu, 13 Dec 2018 12:02:23 +0800
Tag:    v3.6.3

MDL-61535 report_security: SQL Perf improvement