Git commits in Moodle 3.4.x by Didier 'OdyX' Raboud

commit 79172a41fe2050a6a8fa03725b424390b0cb159e
Author: Didier 'OdyX' Raboud <didier.raboud@liip.ch>
Date:   Tue, 19 Jun 2018 23:12:23 +0800
Tag:    v3.4.5

MDL-62753 shibboleth: Logout: fix DB sessions kill