message: Don't check updates if we're offline or an update is already available.
diff: @@ -17,6 +17,10 @@ export class UpdatesService {
  }
  private checkUpdate() {
  + if (this.isAvailable || !navigator.onLine) {
  + return;
  + }
  +
  https.get(
  {
  host: "api.github.com",
  