Git commits in Moodle 3.11.4 by Tien Nguyen

commit 61158222262332a7914b43cf12c5ffb454d6a60e
Author: Tien Nguyen <nguyenphuctien@gmail.com>
Date:   Mon, 19 Jul 2021 09:32:32 +0800
Tag:    v3.11.4

MDL-71961 Quiz: Disable quiz navigation buttons when files are uploading