Merge pull request #966 from RichardScothern/registry-2.1.1

Update Registry to v2.1.1

library/registry

@@ -7,5 +7,6 @@ latest: git://github.com/docker/[email protected]
 0.8.1: git://github.com/docker/[email protected]
 0.9.1: git://github.com/docker/[email protected]
 
-2: git://github.com/docker/distribution-library-image@d5ee820f89fc8ca7b66bd88f70554e89319808e0
-2.1: git://github.com/docker/distribution-library-image@d5ee820f89fc8ca7b66bd88f70554e89319808e0
+2: git://github.com/docker/distribution-library-image@0258654c749c96ca876b1d9ce456bee42b6794de
+2.1: git://github.com/docker/distribution-library-image@0258654c749c96ca876b1d9ce456bee42b6794de
+2.1.1: git://github.com/docker/distribution-library-image@0258654c749c96ca876b1d9ce456bee42b6794de