Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 7f42a9591ca937f81092929356f986a3df111e0c
  - Remove temporarily apt calls

    Change-Id: I661c4db969524661b7f2c76cfe375d9807a21411
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 268bf94..7f42a95 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 268bf94e73014e8e529d5bb0c9bb94853f577b9d
+Subproject commit 7f42a9591ca937f81092929356f986a3df111e0c