- Patch #221230 by Heine: convert requirement error on update to requirement warning.

modules/system/system.install

@@ -276,7 +276,7 @@ function system_requirements($phase) {
     if (!module_exists('update')) {
       $requirements['update status'] = array(
         'value' => $t('Not enabled'),
-        'severity' => REQUIREMENT_ERROR,
+        'severity' => REQUIREMENT_WARNING,
         'description' => $t('Update notifications are not enabled. It is <strong>highly recommended</strong> that you enable the update status module from the <a href="@module">module administration page</a> in order to stay up-to-date on new releases. For more information please read the <a href="@update">Update status handbook page</a>.', array('@update' => 'http://drupal.org/handbook/modules/update', '@module' => url('admin/build/modules'))),
       );
     }