Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 6f496588ed030772c6acf3256fc134515b8e5f05
  - Protect tag in functest.yaml

    Else 3.10 becomes falsy 3.1.

    Change-Id: I84045769d062f184f2f7020b9613cf06abc4af3e
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index c0f1188..6f49658 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit c0f118801c94afe69fa66f686a473bdba18c29fd
+Subproject commit 6f496588ed030772c6acf3256fc134515b8e5f05