ZF2-194: $_SERVER not defined in Zend\Locale\Locale::getBrowser


While working on fixing tests for Zend\Feed, I noticed that Zend\Locale\Locale::getBrowser uses $_SERVER to detect the language/locale. Given that this part of code comes from unit tests, $_SERVER is not defined, thus we need a is_array($_SERVER) check before trying to use it.

Pull request is on it's way.