Pull in new buildrump.sh

Stops unwanted "obj" directory from being created as part of
running ./build-rr.sh

diff --git a/buildrump.sh b/buildrump.sh
index 79685b4421e0f712eaa50f2dde8af7364d9d0f63..d23dbef07ec34542e151dbf9d8d649b70ce76f0b 160000 (submodule)
--- a/buildrump.sh
+++ b/buildrump.sh
@@ -1 +1 @@
-Subproject commit 79685b4421e0f712eaa50f2dde8af7364d9d0f63
+Subproject commit d23dbef07ec34542e151dbf9d8d649b70ce76f0b