fix(livestreaming): window.open params

The target parameter from window.open was missing which was causing
reload in electron.

react/features/recording/components/LiveStream/web/StreamKeyForm.js

      * @returns {void}
      */
     _onOpenHelp() {
-        window.open(this.helpURL, 'noopener');
+        window.open(this.helpURL, '_blank', 'noopener');
     }
 }