Add missing translations for “required” and “optional” strings when checking...

Add missing translations for “required” and “optional” strings when checking PHP extensions installed.

modules/core/www/frontpage_config.php

@@ -177,7 +177,11 @@ $t->data['links_federation'] = $links_federation;
 
 $t->data['enablematrix'] = $enablematrix;
 $t->data['funcmatrix'] = $funcmatrix;
-$t->data['requiredmap'] = array('recommended' => $t->noop('{core:frontpage:recommended}'));
+$t->data['requiredmap'] = array(
+    'recommended' => $t->noop('{core:frontpage:recommended}'),
+    'required' => $t->noop('{core:frontpage:required}'),
+    'optional' => $t->noop('{core:frontpage:optional}'),
+);
 $t->data['version'] = $config->getVersion();
 $t->data['directory'] = dirname(dirname(dirname(dirname(__FILE__))));