Update reference to upstream wdef_tools repo

diff --git a/wdef_tools b/wdef_tools
index 8574af57a90ec6f6621a0a2570984a3550a21fa6..0941f171bbd4665e0eef5956b2f8c87acb8fc3a4 160000 (submodule)
--- a/wdef_tools
+++ b/wdef_tools
@@ -1 +1 @@
-Subproject commit 8574af57a90ec6f6621a0a2570984a3550a21fa6
+Subproject commit 0941f171bbd4665e0eef5956b2f8c87acb8fc3a4