Git commits in Moodle 3.5.5 by Olivier Piton

commit 46f6c0da7bef766018859b4db48190e11bce7f89
Author: Olivier Piton <olivier@cblue.be>
Date:   Thu, 13 Dec 2018 12:02:23 +0800
Tag:    v3.5.5

MDL-61535 report_security: SQL Perf improvement