message: Fix AdhocFilterControl for single metric options
diff: @@ -206,7 +206,7 @@ export default class AdhocFilterControl extends React.Component {
  optionsForSelect(props) {
  const options = [
  ...props.columns,
  - ...[...props.formData.metrics, props.formData.metric].map(metric => (
  + ...[...(props.formData.metrics || []), props.formData.metric].map(metric => (
  metric && (
  typeof metric === 'string' ?
  { saved_metric_name: metric } :
  