Git commits in Moodle 3.7.x by Adrian Hutchinson

commit 9bcfb7425671bdb68d082964d10f86f9b111db7a
Author: Adrian Hutchinson <adrian.hutchinson@mheducation.com>
Date:   Tue, 18 Feb 2020 01:25:14 +0800
Tag:    v3.7.5

MDL-67988 mod_lti: remove padding from JWS base64url encoding