redshift url placeholder

plugins/dbgate-plugin-postgres/src/frontend/drivers.js

@@ -49,6 +49,7 @@ const redshiftDriver = {
   engine: 'redshift@dbgate-plugin-postgres',
   title: 'Amazon Redshift',
   defaultPort: 5439,
+  databaseUrlPlaceholder: 'e.g. redshift-cluster-1.xxxx.redshift.amazonaws.com:5439/dev',
   showConnectionField: (field, values) => ['databaseUrl', 'user', 'password'].includes(field),
   beforeConnectionSave: connection => {
     const { databaseUrl } = connection;