message: fix formatbar not hidden on highlighted message sent
diff: @@ -152,6 +152,7 @@ export default class BasicMessageEditor extends React.Component {
  if (this.props.placeholder) {
  const {isEmpty} = this.props.model;
  if (isEmpty) {
  + this._formatBarRef.hide();
  this._showPlaceholder();
  } else {
  this._hidePlaceholder();
  