minor #94 removed unnecessary locale check (Trainmaster)

This PR was merged into the master branch.

Discussion
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removed unnecessary locale check

If $locale === NULL, the default locale is used. See the php-src: https://github.com/php/php-src/blob/master/ext/intl/formatter/formatter_main.c#L58-L60

Commits
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4be3a42 removed unnecessary locale check

lib/Twig/Extensions/Extension/Intl.php

@@ -54,7 +54,7 @@ function twig_localized_date_filter(Twig_Environment $env, $date, $dateFormat =
     );
 
     $formatter = IntlDateFormatter::create(
-        $locale !== null ? $locale : Locale::getDefault(),
+        $locale,
         $formatValues[$dateFormat],
         $formatValues[$timeFormat],
         $date->getTimezone()->getName(),