Git commits in Moodle 3.5.9 by Paul Holden

commit 7f624852e4fda8d416c4baaf9aba10d75f1d3ae1
Author: Paul Holden <paulh@moodle.com>
Date:   Wed, 24 Jul 2019 18:46:31 +0800
Tag:    v3.5.9

MDL-66228 mod_lesson: ensure return URL parameters are always local.