Update git submodules

* Update docs/submodules/releng from branch 'master'
  to ef1948fc058ccbdea783fc14682f22dd66582953
  - Publish opnfvdocs pieman branch

    Please note it's same commit id as previous release.

    Change-Id: I9518eb9561038af9d9c090f4b03363d6b52945cd
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 171886d..ef1948f 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 171886d18920a9de283a3b4999c140eea6e312f8
+Subproject commit ef1948fc058ccbdea783fc14682f22dd66582953