message: fix ReadReceiptMarker ref
diff: @@ -178,7 +178,7 @@ module.exports = createReactClass({
  render: function() {
  const MemberAvatar = sdk.getComponent('avatars.MemberAvatar');
  if (this.state.suppressDisplay) {
  - return <div />;
  + return <div ref={this._avatar} />;
  }
  const style = {
  