Git commits in Moodle 3.7.1 by Dan Marsden

commit 6ab4eaf7f245f5edb6a185d65271176c92a248f2
Author: Dan Marsden <dan@danmarsden.com>
Date:   Fri, 14 Jun 2019 10:02:13 +0800
Tag:    v3.7.1

MDL-60347 core: debugsmtp should be a developer only setting.