[gnome-build-meta] base-system.bst: Using a fresher base system ref, still debian testing

[Tristan Van Berkom <tvb src gnome org>]

commit 82d08cc75f697d02aaeb7c9b09798ad1cbd41d69
Author: Tristan Van Berkom <tristan vanberkom codethink co uk>
Date:   Tue Feb 13 00:49:57 2018 +0900

    base-system.bst: Using a fresher base system ref, still debian testing

 elements/base/base-system.bst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/elements/base/base-system.bst b/elements/base/base-system.bst
index 86b3170..365db4d 100644
--- a/elements/base/base-system.bst
+++ b/elements/base/base-system.bst
@@ -6,7 +6,7 @@ kind: import
       url: gnome7:repo
       gpg-key: keys/gnome-base.gpg
       track: debian/testing/amd64
-      ref: 4fbb0aeed30fa91aa7dcd685649a0c1a841a1accc8d41acde819f7ea4d527543
+      ref: 21ffaf453fded072dec48b1ac1e7b2087a10ed0ec9c59ca6decac52e84f719bc
 - arch == "i386":
     sources:
     - kind: ostree