Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 060f9d0f13519e5e180038ce2baa5f8ff7009c45
  - Leverage non-root user in Xtesting containers

    Change-Id: Ifefe173d563d4ec7098b47ec6df184d71f760fea
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 63f9569..060f9d0 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 63f9569b21de275831ce545474fa35740076949e
+Subproject commit 060f9d0f13519e5e180038ce2baa5f8ff7009c45