fix the authorized ip regex

ot_admin/Classes/Http/ApiController.php

@@ -17,7 +17,7 @@ class ApiController implements LoggerAwareInterface
     const ALLOWED_IPS = [
         '/^127\.0\.0\.[0-1]$/',
         '/^localhost$/',
-        '/^10\.8\.0\.[0-255]$/'
+        '/^10\.8\.0\.\d{1,3}$/'
     ];
 
     /**