Git commits in Moodle 3.7.3 by Michael Hawkins

commit 87c1819e2f9504789885f16ed4d13ccee97ec3a6
Author: Michael Hawkins <michaelh@moodle.com>
Date:   Tue, 29 Oct 2019 16:29:46 +0800
Tag:    v3.7.3

MDL-66161 output: Escaping fatal error message and URL strings