Git commits in Moodle 3.1.15 by Jun Pataleta

commit 2f982389d40d7286f63489303e1a3c3d6cc6017a
Author: Jun Pataleta <jun@moodle.com>
Date:   Wed, 24 Oct 2018 12:36:56 +0800
Tag:    v3.1.15

MDL-63183 auth_shibboleth: Don't render page when already logged in


commit 41790d2e48322bd8560438aa1e8c7a588caeb0f0
Author: Jun Pataleta <jun@moodle.com>
Date:   Wed, 24 Oct 2018 09:32:48 +0800
Tag:    v3.1.15

MDL-63183 login: Add hidden login token input in guest login forms