message: If new RR-RM API not implemented, fallback to RR-only API
diff: @@ -536,9 +536,16 @@ var TimelinePanel = React.createClass({
  this.props.timelineSet.room.roomId,
  this.state.readMarkerEventId,
  lastReadEvent
  + ).catch((e) => {
  + // /read_markers API is not implemented on this HS, fallback to just RR
  + if (e.errcode === 'M_UNRECOGNIZED') {
  + return MatrixClientPeg.get().sendReadReceipt(
  + lastReadEvent
  ).catch(() => {
  - // it failed, so allow retries next time the user is active
  this.last_rr_sent_event_id = undefined;
  + });
  + }
  + // it failed, so allow retries next time the user is active
  this.last_rm_sent_event_id = undefined;
  });
  