Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 6710296f066592f6497afd51b7359cc4f73ba699
  - Merge "Debug gsutil"
  - Debug gsutil

    Change-Id: Id90f60f43661a9a8e6accc4d1a835497e02552be
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 5c51f64..6710296 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 5c51f640e6f25dd2c8485a571561f5491a0aa1ee
+Subproject commit 6710296f066592f6497afd51b7359cc4f73ba699