Updates utils-git: d879722 Exit if git-update-superproject cannot pull

diff --git a/utils-git b/utils-git
index 9c0e2bc7618ba72cf00acba77b0e12e22a57144a..d879722cd6e782336001099e330a216fb32a1056 160000 (submodule)
--- a/utils-git
+++ b/utils-git
@@ -1 +1 @@
-Subproject commit 9c0e2bc7618ba72cf00acba77b0e12e22a57144a
+Subproject commit d879722cd6e782336001099e330a216fb32a1056