Git commits in Moodle 3.6.6 by Alistair Spark

commit 553732088ea49a9731989ca5e585fe5fb66ea546
Author: Alistair Spark <aspark21@users.noreply.github.com>
Date:   Wed, 07 Aug 2019 07:03:03 +0800
Tag:    v3.6.6

MDL-66071 user: username is required with non-internal auth method