Issue #3523304: Fix for dynamic property creation error.

Issue #3523304: Fix for dynamic property creation error.

src/Routing/RecurlyRouteSubscriber.php

@@ -49,6 +49,13 @@ class RecurlyRouteSubscriber extends RouteSubscriberBase {
    */
   protected $routeOptions = [];
 
+  /**
+   * The custom routes flag.
+   *
+   * @var bool
+   */
+  protected $addRoutes;
+
   /**
    * Constructs a new RouteSubscriber object.
    *