Update git submodules

* Update docs/submodules/releng from branch 'master'
  to 12c5e516cfe4337a45a89ff0c6fd6d9a88f45be3
  - Must increase community.docker becasue of python3-requests

    https://pkgs.alpinelinux.org/packages?name=*requests&branch=v3.18&repo=&arch=x86_64&origin=&flagged=&maintainer=

    Change-Id: I14996bcc2401f33a4daef0ed1e25a5ba4711ec70
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 61a1ef1..12c5e51 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 61a1ef14b4e69d872931eefd3dfd17b266288343
+Subproject commit 12c5e516cfe4337a45a89ff0c6fd6d9a88f45be3