message: use Room.redactionCancelled event
diff: @@ -207,6 +207,8 @@ const TimelinePanel = React.createClass({
  MatrixClientPeg.get().on("Room.timeline", this.onRoomTimeline);
  MatrixClientPeg.get().on("Room.timelineReset", this.onRoomTimelineReset);
  MatrixClientPeg.get().on("Room.redaction", this.onRoomRedaction);
  + // same event handler as Room.redaction as for both we just do forceUpdate
  + MatrixClientPeg.get().on("Room.redactionCancelled", this.onRoomRedaction);
  MatrixClientPeg.get().on("Room.receipt", this.onRoomReceipt);
  MatrixClientPeg.get().on("Room.localEchoUpdated", this.onLocalEchoUpdated);
  MatrixClientPeg.get().on("Room.accountData", this.onAccountData);
  @@ -286,6 +288,7 @@ const TimelinePanel = React.createClass({
  client.removeListener("Room.timeline", this.onRoomTimeline);
  client.removeListener("Room.timelineReset", this.onRoomTimelineReset);
  client.removeListener("Room.redaction", this.onRoomRedaction);
  + client.removeListener("Room.redactionCancelled", this.onRoomRedaction);
  client.removeListener("Room.receipt", this.onRoomReceipt);
  client.removeListener("Room.localEchoUpdated", this.onLocalEchoUpdated);
  client.removeListener("Room.accountData", this.onAccountData);
  