Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "fuel-deploy: Only pass ISO arg for Danube branch"
  - fuel-deploy: Only pass ISO arg for Danube branch

    Post-Danube branches (master, stable/euphrates) do not use an ISO
    argument, so stop passing it.

    While at it, fix some minor coding style and a wrong scenario default.

    Change-Id: I1878f80e685efc2da07dedd1d2c05c51933da2ec
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index cb9d9cc..916c69b 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit cb9d9cc389d947e6c094df8429e8a8fa83a612f1
+Subproject commit 916c69b93b5e3a28e4f36ae18b595fbd808d0e16