Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Clean Xtesting logs as privileged

    It also mutes gsutils and precises Xtesting view regex.

    Change-Id: Idf0457205dc53e9cca2befc139b65715511e8ebf
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 6251581..ce6c6f2 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 62515818796b3b0ef9741ebdef6568cc837b124d
+Subproject commit ce6c6f2434b61eaf0e2524ae90c5158319851c79