minor code improvement

files/src/main/java/de/srsoftware/umbrella/files/FileModule.java

@@ -110,7 +110,9 @@ public class FileModule extends BaseHandler implements FileService {
 		headers.add(CONTENT_TYPE, ct);
 		headers.add(CONTENT_DISPOSITION,"attachment; filename=\""+file.getName()+"\"");
 		ex.sendResponseHeaders(HTTP_OK, 0L);
-		new FileInputStream(file).transferTo(ex.getResponseBody());
+		try (var fos = new FileInputStream(file)){
+			fos.transferTo(ex.getResponseBody());
+		}
 		return true;
 
 	}