--- a/wp/wp-admin/ms-upgrade-network.php	Mon Oct 14 18:06:33 2019 +0200
+++ b/wp/wp-admin/ms-upgrade-network.php	Mon Oct 14 18:28:13 2019 +0200
@@ -9,5 +9,5 @@
 
 require_once( dirname( __FILE__ ) . '/admin.php' );
 
-wp_redirect( network_admin_url('upgrade.php') );
+wp_redirect( network_admin_url( 'upgrade.php' ) );
 exit;