[pygobject] flake8: ignore new W504 warning

[Christoph Reiter <creiter src gnome org>]

commit a450ce09295b9d225d1a1af258ce8eea84087a45
Author: Christoph Reiter <reiter christoph gmail com>
Date:   Fri Oct 26 22:15:05 2018 +0200

    flake8: ignore new W504 warning

 setup.cfg | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/setup.cfg b/setup.cfg
index d01bdfd2..33186d68 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,5 +1,5 @@
 [flake8]
-ignore=E501,E123,E124,E402,E731,E722
+ignore=E501,E123,E124,E402,E731,E722,W504
 exclude=subprojects
 
 [coverage:run]