Git commits in Moodle 3.8.x by Alberto Lara Hernández

commit 40a6b502ae87408fe74121208539647a3bd62d8f
Author: Alberto Lara Hernández <albertolara@moodle.com>
Date:   Fri, 14 Jun 2019 04:34:37 +0800
Tag:    v3.8.0-beta

MDL-65919 core: Skip send headers during phpunit exec in dataformats