add all languages as allowed

src/Gopay/Service.php

@@ -192,7 +192,15 @@ class Service
         self::LANG_CS,
         self::LANG_EN,
         self::LANG_SK,
+        self::LANG_HU,
         self::LANG_DE,
+        self::LANG_FR,
+        self::LANG_IT,
+        self::LANG_ES,
+        self::LANG_PL,
+        self::LANG_RO,
+        self::LANG_BG,
+        self::LANG_HR,
         self::LANG_RU,
     ];