Also load config into IO if not freshly created

src/Composer/Repository/RepositoryFactory.php

@@ -93,10 +93,10 @@ class RepositoryFactory
     {
         if (!$config) {
             $config = Factory::createConfig($io);
+        }
         if ($io) {
             $io->loadConfiguration($config);
         }
-        }
         if (!$rm) {
             if (!$io) {
                 throw new \InvalidArgumentException('This function requires either an IOInterface or a RepositoryManager');