Git commits in Moodle 3.9.0 by fujiwara

commit c4f51bfd31ee8092e5bd1b08869001da267a964f
Author: fujiwara <shintaro.fujiwara@gmail.com>
Date:   Mon, 04 May 2020 20:43:57 +0800
Tag:    v3.9.0-beta

MDL-68415 email: Fix attachment in email_to_user()