Git merges in Moodle 3.6.8 by Jun Pataleta

commit 4d504d86b7d99e2d5f3b168be52f011ddf4b6fe1
Author: Jun Pataleta <jun@moodle.com>
Date:   Tue, 31 Dec 2019 15:18:49 +0800
Tag:    v3.6.8

Merge branch 'MDL-63996-36' of git://github.com/andrewnicols/moodle into MOODLE_36_STABLE