Adding the extended messages for exceptions

i18n/I18N.php

@@ -30,7 +30,7 @@ class I18N
         $config = Config::get(__CLASS__);
 
         if (!is_array($config['locales'])) {
-            throw new InitializationException('locales empty');
+            throw new InitializationException('key \'locales\' array\'s config is empty');
         }
 
         self::$locales = $config['locales'];