fix new setting default value handling.

public/app/plugins/datasource/mssql/module.ts

@@ -1,9 +1,6 @@
 import { MssqlDatasource } from './datasource';
 import { MssqlQueryCtrl } from './query_ctrl';
-
-class MssqlConfigCtrl {
-  static templateUrl = 'partials/config.html';
-}
+import { MssqlConfigCtrl } from './config_ctrl';
 
 const defaultQuery = `SELECT
     <time_column> as time,