Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Add jobs for Iruya release

    It will allow generating all Functest stable branches [1]

    [1] https://gerrit.opnfv.org/gerrit/#/c/67401/

    Change-Id: I95950c30c9e3cf7ea119063dff77cd0aff9b0b69
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 5f0a1c5..15a4412 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 5f0a1c50bdda4e000b2cbe3cd680553f1a02124e
+Subproject commit 15a44127d6c45fb224cdf35e4620ccaf8091a3f1