Trad: Update translation files

htdocs/langs/ar_AR/admin.lang

htdocs/langs/ar_AR/paybox.lang

htdocs/langs/da_DA/paybox.lang

htdocs/langs/de_DE/paybox.lang

htdocs/langs/fi_FI/paybox.lang

htdocs/langs/is_IS/admin.lang

htdocs/langs/is_IS/paybox.lang

htdocs/langs/is_IS/users.lang

htdocs/langs/it_IT/paybox.lang

htdocs/langs/nb_NO/paybox.lang

htdocs/langs/nl_BE/paybox.lang

htdocs/langs/nl_NL/paybox.lang

htdocs/langs/pl_PL/paybox.lang

htdocs/langs/pt_PT/paybox.lang

htdocs/langs/ro_RO/paybox.lang

htdocs/langs/ru_RU/paybox.lang

htdocs/langs/sl_SL/paybox.lang

htdocs/langs/tr_TR/admin.lang

htdocs/langs/tr_TR/paybox.lang

htdocs/langs/zh_CN/paybox.lang