Git commits in Moodle 3.7.0 by Cameron Ball

commit f321b0515a197eb3c23bafe81951c047488d581a
Author: Cameron Ball <cameron@moodle.com>
Date:   Thu, 21 Mar 2019 16:04:37 +0800
Tag:    v3.7.0-beta

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