Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 9e593807564b5c95d0b747840be09a631ebe49a0
  - Merge "Clean docker.service.d/http-proxy.conf as root"
  - Clean docker.service.d/http-proxy.conf as root

    Change-Id: Ic05f190e7cd95d0eb93012d47fcbb5dc9a81c1b6
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 1dc96dc..9e59380 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 1dc96dc51b0e0326c22d4fff1ea07e6d4f8c8e30
+Subproject commit 9e593807564b5c95d0b747840be09a631ebe49a0