Fix newline

Author: OskarStark

src/Symfony/Component/DependencyInjection/Loader/XmlFileLoader.php

@@ -429,7 +429,7 @@ private function parseFileToDOM(string $file): \DOMDocument
                 }
             }
             if ($errors) {
-                throw new InvalidArgumentException(sprintf('Unable to parse file "%s": ', $file).implode("/n", $errors), $e->getCode(), $e);
+                throw new InvalidArgumentException(sprintf('Unable to parse file "%s": ', $file).implode("\n", $errors), $e->getCode(), $e);
             }
         }