Bug#1126850: [debian-mysql] Bug#1126850: Bug#1126850: mariadb-server: "mysqldump --system=users" fails with error "Illegal mix of collations"

[Daniel Black]

MDEV-37442 Illegal mix of collations during "mariadb-dump --system=user"
+ https://github.com/MariaDB/server/pull/4549

Upstream in review.