Git merges in Moodle 4.0.0 by AMOS bot

commit 2b7c85cc4e06283bda557cce44f896123b0c103f
Author: AMOS bot <amos@moodle.org>
Date:   Sat, 12 Dec 2020 08:07:58 +0800
Tag:    v4.0.0-beta

Merge branch 'master' into install_master