Git commits in Moodle 3.5.6 by Julien Boulen

commit 849f7f40c881dfa1f92a76e8a63769797e1ef4ae
Author: Julien Boulen <julien.boulen@univ-rennes2.fr>
Date:   Mon, 18 Mar 2019 18:17:58 +0800
Tag:    v3.5.6

MDL-46803 course: Prevent unenrol users with multiple roles during reset