Author: Dan Marsden
MDL-60347 core: debugsmtp should be a developer only setting.
http://git.moodle.org/gw?p=moodle.git;a=commit;h=6ab4eaf7f245f5edb6a185d65271176c92a248f2
http://github.com/moodle/moodle/commit/6ab4eaf7f245f5edb6a185d65271176c92a248f2
+ 3.7 en [configdebugsmtp,core_admin]