init info_json variable as array

index.php

@@ -28,6 +28,7 @@
         {
                 $rnd_data = mt_rand(10000,99999);
                 mkdir(_DATA_DIR . "/" . $rnd_data);
+                $info_json = array();
                 $info_json->expire = time() + (7 * 24 * 60 * 60);
                 file_put_contents(_DATA_DIR . "/" . $rnd_data . "/info.json", json_encode($info_json));