Git commits in Moodle 2.7.19 by Andrew Nicols

commit 43235c6236ba5362c5990c487a31085cde173c35
Author: Andrew Nicols <andrew@nicols.co.uk>
Date:   Thu, 19 Jan 2017 13:47:40 +0800
Tag:    v2.7.19

MDL-57639 mod_forum: Update to use correct variable name