Git commits in Moodle 3.6.3 by Dmitrii Metelkin

commit bf2e077fc8fc72dda95843fb10b3c3ada1be1464
Author: Dmitrii Metelkin <dmitriim@catalyst-au.net>
Date:   Wed, 03 Oct 2018 15:13:49 +0800
Tag:    v3.6.3

MDL-63516 groups: fix unexpected debugging message