Git commits in Moodle 3.3.4 by Jakob Ackermann

commit ff6faa59eba34e08223d6bee5508f4687a6e6755
Author: Jakob Ackermann <jackermann@onlineschool.ca>
Date:   Thu, 12 Oct 2017 05:28:58 +0800
Tag:    v3.3.4

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