Git commits in Moodle 3.9.7 by Tim Schroeder

commit 054d5c0f04eb88c923fdaebabf552f45437729f6
Author: Tim Schroeder <t.schroeder@itc.rwth-aachen.de>
Date:   Tue, 03 Nov 2020 18:53:32 +0800
Tag:    v3.9.7

MDL-70110 assign: fixed ws get_submissions for groups