Add missing migration to schema

Otherwise creating a new database would fail in PostgreSQL (or
specifically, running migrations for it).

Fixes #550

db/schema.gotxt

@@ -331,6 +331,7 @@ insert into version values
 	('2021-04-01-1-store-warn'),
 	('2021-04-02-1-cluster-paths'),
 	('2021-04-07-1-billing-anchor'),
-	('2021-06-27-1-public');
+	('2021-06-27-1-public'),
+	('2021-11-15-1-user-role');
 
 -- vim:ft=sql:tw=0