Git commits in Moodle 3.6.0 by Didier 'OdyX' Raboud

commit 90ae1b90f13f7726ab8f15cbe27ab6e9ea6a907c
Author: Didier 'OdyX' Raboud <didier.raboud@liip.ch>
Date:   Tue, 19 Jun 2018 23:12:23 +0800
Tag:    v3.6.0-beta

MDL-62753 shibboleth: Logout: fix DB sessions kill