fix check slug

src/Controller/api/PollController.php

@@ -411,7 +411,7 @@ class PollController extends FramadateController {
 		return $this->json( [
 			'message' => ' yes this slug is available on this Framadate instance ',
 			'data'    => [
-				'slug' => $customUrl,
+				'slug' => $slug,
 			],
 		],
 			404 );