Git commits in Moodle 3.2.3 by Ruslan Kabalin

commit f7e9dbcbe21a30abb8633bef57c02762f0e2334d
Author: Ruslan Kabalin <r.kabalin@lancaster.ac.uk>
Date:   Fri, 07 Apr 2017 18:57:35 +0800
Tag:    v3.2.3

MDL-58539 assignfeedback_editpdf: Fix group assignment fatal error.