Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 7cd7306c128433d979de5d8d14ee1fd7f9c81ad8
  - Disable cold migration in Functest gates

    Change-Id: I092baa82bd22cc19c0786a14f962db9bcb7deadb
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index cc1e598..7cd7306 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit cc1e598de780895d921e126f6032a6b36e5de250
+Subproject commit 7cd7306c128433d979de5d8d14ee1fd7f9c81ad8