Git commits in Moodle 3.7.5 by Huong Nguyen

commit 6aaa78f04432bbf859dc719002426c4309c5ae4a
Author: Huong Nguyen <huongnv13@gmail.com>
Date:   Wed, 12 Feb 2020 16:45:04 +0800
Tag:    v3.7.5

MDL-67942 Quiz: Quiz attempt report delete_selected_attempts issue