Git commits in Moodle 3.8.9 by Mathew May

commit 2f6ff54b11480bcacb906f198484041b643b52e0
Author: Mathew May <mathewm@hotmail.co.nz>
Date:   Thu, 22 Apr 2021 13:26:10 +0800
Tag:    v3.8.9

MDL-70622 mod_lti: Tighten redirect param typing