Update git submodules

* Update docs/submodules/releng from branch 'master'
  to d6bb3fe8574bf5acd790339aaf1a7fb3c8cd7d31
  - Revert "Try LaaS via leguer gates"

    The server is currently offline

    Change-Id: I4ed72547061a7f013f261df91879c55bcaa3b9eb
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index b2d1bf8..d6bb3fe 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit b2d1bf8e0916902cbd17f5e8c8fd8768126367bc
+Subproject commit d6bb3fe8574bf5acd790339aaf1a7fb3c8cd7d31