Git commits in Moodle 3.7.3 by David Matamoros

commit 4be324b42a0b89734557ba06ed42f04c1d28ec2a
Author: David Matamoros <davidmc@moodle.com>
Date:   Mon, 02 Sep 2019 20:52:01 +0800
Tag:    v3.7.3

MDL-66354 core_calendar: Notices in error.log on calendar events