Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Clean all containers as first step

    It overprotects vs aborted jobs or failures in CI.
    It fixes few urls printed in console.

    Change-Id: Ibbaacfd9d51c5424c5632fcdeaedf619fd946006
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index ceb545e..b738c41 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit ceb545e311cc9f8adcc8e617346b9cb63af16f5c
+Subproject commit b738c417b0f36a611eb5d6b2a05f2244f58c7ac0