Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 20f09e500c79777627c5b569d4c717c60db53c51
  - Conforms with jjb 5.x+

    It also updates to last jjb release and py12

    Change-Id: I7c2185c171d79d97c9f818bbb0db61e6ed6eeac8
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 09b5660..20f09e5 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 09b56602efe05a442d3469697cf07c876774ed04
+Subproject commit 20f09e500c79777627c5b569d4c717c60db53c51