Update git submodules

* Update docs/submodules/daisy from branch 'master'
  - docker load latest registry server during runtime

    Using http://daisycloud.org/static/files/registry-server.tar is unsafe.

    Please see upstream patch https://review.openstack.org/#/c/554085/ which
    implements docker load latest registry server during runtime.

    Change-Id: I42f27f522f328619e19a69e0fa796f7b8efa9bd0
    Signed-off-by: Zhijiang Hu <hu.zhijiang@zte.com.cn>

diff --git a/docs/submodules/daisy b/docs/submodules/daisy
index 0f6f121..e791b00 160000 (submodule)
--- a/docs/submodules/daisy
+++ b/docs/submodules/daisy
@@ -1 +1 @@
-Subproject commit 0f6f12141ae7997713cbab0296038579376b476d
+Subproject commit e791b002ecc023b2df94fbc72f7673403268b65a