Update git submodules

* Update docs/submodules/releng from branch 'master'
  to b1c884de6d9a0f3c1bfe9d2208447d4892dc67ff
  - Merge "Prepare backporting xrally_kubernetes"
  - Prepare backporting xrally_kubernetes

    Change-Id: I58fdb2d168b92622d949fb7a51b66364b4307771
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 75876f1..b1c884d 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 75876f1a2b282c3d63d078fbddf1b5afec91f30f
+Subproject commit b1c884de6d9a0f3c1bfe9d2208447d4892dc67ff