message: [bugfix] add item is missing on table editor metrics tab
diff: @@ -456,6 +456,7 @@ export class DatasourceEditor extends React.PureComponent {
  </FormContainer>
  }
  collection={this.state.datasource.metrics}
  + allowAddItem
  onChange={this.onDatasourcePropChange.bind(this, 'metrics')}
  itemGenerator={() => ({
  metric_name: '<new metric>',
  