Fix prefix based on locale

Similar RoutesResponse instantiation is done in https://github.com/FriendsOfSymfony/FOSJsRoutingBundle/blob/master/Controller/Controller.php#L97. But without this fix, outputs from controller and command are not equal, when JMSI18nRoutingBundle + `--locale` option are used.
Conflicts:
	Command/DumpCommand.php

Author: akovalyov

Command/DumpCommand.php

@@ -112,7 +112,7 @@ private function doDump(InputInterface $input, OutputInterface $output)
             new RoutesResponse(
                 $baseUrl,
                 $this->getExposedRoutesExtractor()->getRoutes(),
-                $input->getOption('locale'),
+                $this->getExposedRoutesExtractor()->getPrefix($input->getOption('locale')),
                 $this->getExposedRoutesExtractor()->getHost(),
                 $this->getExposedRoutesExtractor()->getScheme()
             ),