message: Correctly unregister group store listener when unmounting RoomList
diff: @@ -97,7 +97,7 @@ module.exports = React.createClass({
  if (tag[0] !== '+') {
  return;
  }
  - this.groupStoreToken = GroupStore.registerListener(tag, () => {
  + this._groupStoreToken = GroupStore.registerListener(tag, () => {
  // This group's rooms or members may have updated, update rooms for its tag
  this.updateVisibleRoomsForTag(dmRoomMap, tag);
  this.updateVisibleRooms();
  @@ -179,7 +179,9 @@ module.exports = React.createClass({
  }
  // NB: GroupStore is not a Flux.Store
  + if (this._groupStoreToken) {
  this._groupStoreToken.unregister();
  + }
  // cancel any pending calls to the rate_limited_funcs
  this._delayedRefreshRoomList.cancelPendingCall();
  