message: Get rid of react key warning when no results
diff: @@ -254,7 +254,7 @@ export default class Dropdown extends React.Component {
  );
  });
  if (options.length === 0) {
  - return [<div className="mx_Dropdown_option">
  + return [<div key="0" className="mx_Dropdown_option">
  No results
  </div>];
  }
  