detect postgres version for saved datasources

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

@@ -1,24 +1,6 @@
 import { PostgresDatasource } from './datasource';
 import { PostgresQueryCtrl } from './query_ctrl';
-
-class PostgresConfigCtrl {
-  static templateUrl = 'partials/config.html';
-
-  current: any;
-
-  /** @ngInject **/
-  constructor($scope) {
-    this.current.jsonData.sslmode = this.current.jsonData.sslmode || 'verify-full';
-  }
-
-  // the value portion is derived from postgres server_version_num/100
-  postgresVersions = [
-    { name: '9.3.x', value: 903 },
-    { name: '9.4.x', value: 904 },
-    { name: '9.5.x', value: 905 },
-    { name: '9.6.x', value: 906 },
-  ];
-}
+import { PostgresConfigCtrl } from './config_ctrl';
 
 const defaultQuery = `SELECT
   extract(epoch from time_column) AS time,