Git commits in Moodle 3.4.1 by Jakob Ackermann

commit 3cfc322bdf9982d361912b8c3143d83845e5c51e
Author: Jakob Ackermann <jackermann@onlineschool.ca>
Date:   Thu, 12 Oct 2017 05:28:58 +0800
Tag:    v3.4.1

MDL-60187 mod_lti: Do not create a grade item when grades are disabled.