Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "Fix xci job triggering for docs build"
  - Fix xci job triggering for docs build

    This patch should unblock:
    https://gerrit.opnfv.org/gerrit/#/c/40533/

    Change-Id: I72e827b0feae559e6477d213d0f752ed04cd62b3
    Signed-off-by: agardner <agardner@linuxfoundation.org>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index a3ef9d8..c7f4069 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit a3ef9d8f755464ac8af4cc19efae970d69251010
+Subproject commit c7f40696b6223a945d38634e423ebcb2888d98fd