Git commits in Moodle 3.9.0 by deraadt

commit 5143106813686211bd807a52b18aa888a66fec77
Author: deraadt <michaelderaadt@gmail.com>
Date:   Thu, 16 Apr 2020 09:47:45 +0800
Tag:    v3.9.0-beta

MDL-68425 user: Add capability check for messaging