corrected hardcoded matrix domain and added code to remove old matrix-make-user-admin script per suggestion.

roles/matrix-postgres/tasks/setup_postgres.yml

@@ -80,6 +80,12 @@
     mode: 0750
   when: matrix_postgres_enabled|bool
 
+- name: (Migration) Ensure old matrix-make-user-admin script deleted
+  file:
+    path: "/usr/local/bin/matrix-make-user-admin"
+    state: absent
+  when: matrix_postgres_enabled|bool
+
 - name: Ensure matrix-postgres-update-user-password-hash script created
   template:
     src: "{{ role_path }}/templates/usr-local-bin/matrix-postgres-update-user-password-hash.j2"

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

@@ -16,4 +16,4 @@ docker run \
 	--env-file=/matrix/postgres/env-postgres-psql \
 	--network matrix \
 	postgres:12.1-alpine \
-	psql -h matrix-postgres -c "UPDATE users set admin=$2 WHERE name like '@$1:seattlematrix.org'"
+	psql -h matrix-postgres -c "UPDATE users set admin=$2 WHERE name like '@$1:{{ matrix_domain }}'"