libmowgli-2/: bump to latest HEAD

diff --git a/libmowgli-2 b/libmowgli-2
index 12c57bf765603d53decabcdd4cecd3c845a85000..ffc46e5f3d3b8bfcf5aaa0832dcd944bbf415e9b 160000 (submodule)
--- a/libmowgli-2
+++ b/libmowgli-2
@@ -1 +1 @@
-Subproject commit 12c57bf765603d53decabcdd4cecd3c845a85000
+Subproject commit ffc46e5f3d3b8bfcf5aaa0832dcd944bbf415e9b