Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "decouple the mutual-dependence of config.py and server.py"
  - decouple the mutual-dependence of config.py and server.py

    Currently server.py relies on CONF while starting the service, and
    config.py's config_fie is set in server.py, which is wrongly bi-depended
    this patch aims to let Config parse the sys.argv personally,
    just as oslo.config do, so that decouple the mutual-dependency

    Change-Id: I46887d122a98d478caebe9eeb7ab038941ce1f6b
    Signed-off-by: SerenaFeng <feng.xiaowei@zte.com.cn>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 788527a..cbcabf6 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 788527a8e1d34aaf2abb9218260d07934a44354d
+Subproject commit cbcabf6643e68c019b407c95b1526e77337f7697