message: remove dupe method
diff: @@ -235,10 +235,6 @@ export default class MessageComposer extends React.Component {
  }
  };
  - componentWillUnmount() {
  - dis.unregister(this.dispatcherRef);
  - }
  -
  componentDidMount() {
  this.dispatcherRef = dis.register(this.onAction);
  MatrixClientPeg.get().on("RoomState.events", this._onRoomStateEvents);
  @@ -269,6 +265,7 @@ export default class MessageComposer extends React.Component {
  if (this._roomStoreToken) {
  this._roomStoreToken.remove();
  }
  + dis.unregister(this.dispatcherRef);
  }
  _onRoomStateEvents(ev, state) {
  