Git commits in Moodle 3.6.x by Cameron Ball

commit 3282dda765c972d69d2a5d2d431b6c844ccc8a0c
Author: Cameron Ball <cameron@moodle.com>
Date:   Thu, 21 Mar 2019 16:04:37 +0800
Tag:    v3.6.4

MDL-65104 registration: Ensure $registration is always null when no record exists