Git commits in Moodle 3.6.7 by Mark Johnson

commit c63863df2bfa2baca2f08ef2339cadeef3c8ad38
Author: Mark Johnson <mark.johnson@open.ac.uk>
Date:   Thu, 11 Apr 2019 16:02:31 +0800
Tag:    v3.6.7

MDL-65335 auth: Make oauth2 enabled check more efficient