message: Fix soft crash around threads when room isn't yet in store
diff: @@ -402,8 +402,7 @@ export class UnwrappedEventTile extends React.Component<IProps, IState> {
  }
  private setupNotificationListener = (thread: Thread): void => {
  - const room = MatrixClientPeg.get().getRoom(this.props.mxEvent.getRoomId());
  - const notifications = RoomNotificationStateStore.instance.getThreadsRoomState(room);
  + const notifications = RoomNotificationStateStore.instance.getThreadsRoomState(thread.room);
  this.threadState = notifications.getThreadRoomState(thread);
  