message: Fix listener leak in TagPanel
diff: /*
  Copyright 2017, 2018 New Vector Ltd.
  +Copyright 2020 The Matrix.org Foundation C.I.C.
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
  @@ -64,8 +65,8 @@ const TagPanel = createReactClass({
  this.unmounted = true;
  this.context.removeListener("Group.myMembership", this._onGroupMyMembership);
  this.context.removeListener("sync", this._onClientSync);
  - if (this._filterStoreToken) {
  - this._filterStoreToken.remove();
  + if (this._tagOrderStoreToken) {
  + this._tagOrderStoreToken.remove();
  }
  },
  