fixed

Closes #3356899

src/Controller/CacheflushApi.php

@@ -185,7 +185,7 @@ class CacheflushApi extends ControllerBase {
     $this->container->get('kernel')->invalidateContainer();
 
     // Rebuild module and theme data.
-    $module_data = system_rebuild_module_data();
+    $module_data = $this->moduleHandler()->getModuleList();
     /** @var \Drupal\Core\Extension\ThemeHandlerInterface $theme_handler */
     $theme_handler = $this->container->get('theme_handler');
     $theme_handler->refreshInfo();