Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Update global jjb v0.24.6

    From the release notes:
    Upgrade to global-jjb v0.24.6 before performing this upgrade. This
    ensures that jjb-verify job pulls in a regex fix that will allow it to
    verify the v0.25.0 upgrade.

    Change-Id: I48335de599b46b7e6c70f8bb77fb8c254cfe85f4
    Signed-off-by: Aric Gardner <agardner@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index d02f5f6..ccec11c 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit d02f5f6c121a2f5a660bd40d07c3c4e61a5c0186
+Subproject commit ccec11c5ad10c5dc40deb3907af01b7f86170cb9