Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 61a1ef14b4e69d872931eefd3dfd17b266288343
  - Remove docker install in all docker gates

    Change-Id: I5a9473dabb42a2ccf2c636a35b4898258b75bb56
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index fdef7fe..61a1ef1 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit fdef7fe278aa085952338a1973d03622feb56319
+Subproject commit 61a1ef14b4e69d872931eefd3dfd17b266288343