Update git submodules

* Update docs/submodules/releng from branch 'master'
  to af1f949087ec6d682c46822316b2c2ad2c2d7c6c
  - Leverage on S3 support provided Xtesting

    It avoids using gsutil in Jenkins (extra logics).

    Change-Id: I2f3d69b88b115469e25b1452590e9ffc66266455
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 2d1656e..af1f949 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 2d1656e1df9421811315cc23a54b7fe57f215c17
+Subproject commit af1f949087ec6d682c46822316b2c2ad2c2d7c6c