message: Fix accessing room prop which is optional
diff: @@ -498,9 +498,10 @@ export default class RoomPreviewBar extends React.Component<IProps, IState> {
  }
  const myUserId = MatrixClientPeg.get().getUserId();
  - const memberEventContent = this.props.room.currentState.getMember(myUserId).events.member.getContent();
  + const member = this.props.room?.currentState.getMember(myUserId);
  + const memberEventContent = member?.events.member?.getContent();
  - if (memberEventContent.reason) {
  + if (memberEventContent?.reason) {
  reasonElement = (
  <InviteReason
  reason={memberEventContent.reason}
  