[Translation] [Loco] Send If-Modified-Since header when possible

Author: Kocal

Resources/config/translation_providers.php

@@ -51,6 +51,7 @@
                 service('logger'),
                 param('kernel.default_locale'),
                 service('translation.loader.xliff'),
+                service('translator'),
             ])
             ->tag('translation.provider_factory')