downgrade to kirby v3

kirby/src/Cms/Visitor.php

@@ -2,7 +2,6 @@
 
 namespace Kirby\Cms;
 
-use Kirby\Http\Visitor as BaseVisitor;
 use Kirby\Toolkit\Facade;
 
 /**
@@ -16,7 +15,10 @@ use Kirby\Toolkit\Facade;
  */
 class Visitor extends Facade
 {
-	public static function instance(): BaseVisitor
+	/**
+	 * @return \Kirby\Http\Visitor
+	 */
+	public static function instance()
 	{
 		return App::instance()->visitor();
 	}