Update git submodules

* Update docs/submodules/releng from branch 'master'
  - bugfix: TestAPI auto deploy success but shown as fail

    when execute 'curl -s --head  --request GET http://testresults.opnfv.org/test'
    'HTTP/1.1 301 Moved Permanently' will be returned rather than 200 OK,
    result in the connectivity check fail. To fix this problem,
    use 'http://testresults.opnfv.org/test/' instead.

    Change-Id: I5d6916c15858b3f431a2ab18aeef7f352cb9e31b
    Signed-off-by: SerenaFeng <feng.xiaowei@zte.com.cn>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index b1965dc..aa7c1b4 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit b1965dcda6bd0fd452e73d60bdd8aa258d2d27f1
+Subproject commit aa7c1b474fa2d371ef87212abee08469c190dda4