Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 15252d8417f7a25c29ab2835a5b13e27e934fe34
  - Fix functest-kubernetes trivy view

    Else it prints the functest-kubernetes-ng docker jobs.

    Change-Id: I29c0da92b34a975cf421711967eb4e8703621031
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 6c8e1af..15252d8 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 6c8e1af2e5f78ff2d673175899ed6de56a99d8dd
+Subproject commit 15252d8417f7a25c29ab2835a5b13e27e934fe34