Bring cbs up to date

diff --git a/external/cbs b/external/cbs
index a7ad152e9248d770b63684c5e019348457100a1e..4437b7cd6524ffcb9d824fbd5abc8b620a58939e 160000 (submodule)
--- a/external/cbs
+++ b/external/cbs
@@ -1 +1 @@
-Subproject commit a7ad152e9248d770b63684c5e019348457100a1e
+Subproject commit 4437b7cd6524ffcb9d824fbd5abc8b620a58939e