Issue #2219009 follow-up by pwolanin: Replace missed call to settings().

index.php

@@ -16,7 +16,7 @@
 }
 catch (Exception $e) {
   $message = 'If you have just changed code (for example deployed a new module or moved an existing one) read <a href="http://drupal.org/documentation/rebuild">http://drupal.org/documentation/rebuild</a>';
-  if (settings()->get('rebuild_access', FALSE)) {
+  if (\Drupal\Component\Utility\Settings::get('rebuild_access', FALSE)) {
     $rebuild_path = $GLOBALS['base_url'] . '/rebuild.php';
     $message .= " or run the <a href=\"$rebuild_path\">rebuild script</a>";
   }