Git commits in Moodle 3.7.7 by Bas Brands

commit 5611585eec3e3dd936ebbd5f3c05a02aaef095ee
Author: Bas Brands <bas@moodle.com>
Date:   Wed, 03 Jun 2020 23:40:33 +0800
Tag:    v3.7.7

MDL-68864 qtype_multichoice: clearchoice