Проблемы с gettext php

Не работает перевод текста через gettext. Помогите пожалуйста

$translate = 'messages';
putenv("LC_ALL=ru_RU");
T_setlocale(LC_ALL, "ru_RU");
bindtextdomain($translate, _ROOT_DIR_."locale/");
textdomain($translate);
bind_textdomain_codeset($translate, 'UTF-8');

Структура папок :

locale -> ru_RU -> LC_MESSAGES -> messages.mo messages.po

Код messages.po :

msgid ""
msgstr ""
"Project-Id-Version: \n"
"POT-Creation-Date: 2017-05-03 13:06+0300\n"
"PO-Revision-Date: 2017-05-03 13:06+0300\n"
"Last-Translator: \n"
"Language-Team: \n"
"Language: ru_RU\n"
"MIME-Version: 1.0\n"
"Content-Type: text/plain; charset=UTF-8\n"
"Content-Transfer-Encoding: 8bit\n"
"X-Generator: Poedit 2.0.1\n"
"X-Poedit-Basepath: ../../..\n"
"Plural-Forms: nplurals=3; plural=(n%10==1 && n%100!=11 ? 0 : n%10>=2 && n"
"%10<=4 && (n%100<10 || n%100>=20) ? 1 : 2);\n"
"X-Poedit-SearchPath-0: .\n"
#: index.php:5
msgid "Hello world"
msgstr "Привет мир"