Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 3012ed3ded6bd84ea7febc1b54cd6ef4b0d4ce47
  - Prepare v1.27 and v1.28 release jobs

    Change-Id: Ib362e42ad0c0ea606198b50c53a6502e95bd4a73
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index b18589b..3012ed3 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit b18589bcc4939f590502710d2d77ceff3a4aa394
+Subproject commit 3012ed3ded6bd84ea7febc1b54cd6ef4b0d4ce47