Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 9972148fd8afbe8be42aad7ab61f9692084860db
  - Publish a generic tox

    It filters on active branches.

    Change-Id: I66f9e39af62a761d5d4f8b94c617f93e48e1fcef
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index bf5675b..9972148 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit bf5675bdba1bf204326b38e29c1e4b096e36a5ed
+Subproject commit 9972148fd8afbe8be42aad7ab61f9692084860db