Git commits in Moodle 3.9.0 by Stephen Vickers

commit 5140a7bb11e757729cf6935916cd56ac32e3b27a
Author: Stephen Vickers <stephen@spvsoftwareproducts.com>
Date:   Wed, 26 Feb 2020 05:01:52 +0800
Tag:    v3.9.0-beta

MDL-68049 mod_lti: Fix link-level memberships service