Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Fix Functest Docker multijob

    It mainly fixes the project names in the multijob and removes the
    triggers added by "Add build triggers and source code management" [1].

    It should be noted that creating manifest shouldn't be done via one
    job per arch.

    [1] https://gerrit.opnfv.org/gerrit/#/c/46789/

    Change-Id: I2cb078ffb900513d4404a39936703844916d84e4
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 323368a..78508cc 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 323368adf57395f8cb3dab33d04bad453b433eb2
+Subproject commit 78508ccfafbe7c87c79ee9d77af9b3efbebe6848