Git commits in Moodle 3.4.6 by Peter Spicer

commit 7e4872e91eb35a09b0fe7476b6553ac97425bf60
Author: Peter Spicer <peter.spicer@catalyst-eu.net>
Date:   Wed, 10 Oct 2018 17:31:00 +0800
Tag:    v3.4.6

MDL-63451 core_message: Properly escape URLs for notification popup