message: Fix add reaction prompt showing even when user is not joined to room
diff: @@ -198,7 +198,8 @@ export default class ReactionsRow extends React.PureComponent<IProps, IState> {
  const cli = this.context;
  let addReactionButton;
  - if (cli.getRoom(mxEvent.getRoomId()).currentState.maySendEvent(EventType.Reaction, cli.getUserId())) {
  + const room = cli.getRoom(mxEvent.getRoomId());
  + if (room.getMyMembership() === "join" && room.currentState.maySendEvent(EventType.Reaction, cli.getUserId())) {
  addReactionButton = <ReactButton mxEvent={mxEvent} reactions={reactions} />;
  }
  