message: Fix possible infinite loop on widget start
  * fix 15494 infinit loop on widget start error
  * change message to error from log
  and fix block style
diff: @@ -227,7 +227,7 @@ export default class AppTile extends React.Component<IProps, IState> {
  this.sgWidget.on("ready", this.onWidgetReady);
  this.startWidget();
  } catch (e) {
  - logger.log("Failed to construct widget", e);
  + logger.error("Failed to construct widget", e);
  this.sgWidget = null;
  }
  }
  @@ -241,7 +241,13 @@ export default class AppTile extends React.Component<IProps, IState> {
  private iframeRefChange = (ref: HTMLIFrameElement): void => {
  this.iframe = ref;
  if (ref) {
  - if (this.sgWidget) this.sgWidget.start(ref);
  + try {
  + if (this.sgWidget) {
  + this.sgWidget.start(ref);
  + }
  + } catch (e) {
  + logger.error("Failed to start widget", e);
  + }
  } else {
  this.resetWidget(this.props);
  }
  