Fix hardcoded values in postgres script matrix-change-user-admin-status

roles/matrix-postgres/templates/usr-local-bin/matrix-change-user-admin-status.j2

@@ -11,9 +11,9 @@ fi
 docker run \
 	-it \
 	--rm \
-	--user=991:991 \
+	--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
 	--cap-drop=ALL \
 	--env-file={{ matrix_postgres_base_path }}/env-postgres-psql \
 	--network {{ matrix_docker_network }} \
-	postgres:12.1-alpine \
+	{{ matrix_postgres_docker_image_to_use }} \
-	psql -h matrix-postgres -c "UPDATE users set admin=$2 WHERE name like '@$1:{{ matrix_domain }}'"
+	psql -h {{ matrix_postgres_connection_hostname }} -c "UPDATE users set admin=$2 WHERE name like '@$1:{{ matrix_domain }}'"