Git commits in Moodle 3.8.3 by Dani Palou

commit fef31ac7c1c3003ae5d38239492a846c5a1509fb
Author: Dani Palou <dani@moodle.com>
Date:   Thu, 05 Mar 2020 18:47:35 +0800
Tag:    v3.8.3

MDL-67189 external: Add test to catch PHP exceptions


commit 3f128fff10d4fb9c357cc3e117a7d43cc1dd02f9
Author: Dani Palou <dani@moodle.com>
Date:   Wed, 12 Feb 2020 17:14:52 +0800
Tag:    v3.8.3

MDL-67189 external: Catch Throwable in call_external_function