Add LB setting to new user settings

Put under labs out of concern for https://github.com/vector-im/riot-meta/issues/66

src/settings/controllers/LowBandwidthController.js

@@ -0,0 +1,24 @@
+/*
+Copyright 2019 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.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import SettingController from "./SettingController";
+import PlatformPeg from "../../PlatformPeg";
+
+export default class LowBandwidthController extends SettingController {
+    onChange(level, roomId, newValue) {
+        PlatformPeg.get().reload();
+    }
+}