Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - states: maas: Add 30s delay in re-deploy attempt

    Occasionaly, MaaS fails to provision/deploy some nodes, in which
    case we try marking them as broken, then fixed (to put them again
    in 'ready' state); before re-attempting the MaaS deploy operation.
    However, this leads to 'Error: Internal server error' when deploy
    function is called right after transitioning the node to 'ready'
    state.

    Add a delay of 30 seconds before re-attempting the failed operation.

    Change-Id: Ia9ecec67639387e4a29feab3114e1741c554a2cb
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 4489699..39ffab9 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 4489699cb63fadb6939d5c70b49e84bb4f1ff17f
+Subproject commit 39ffab99ad34ff45c0ed8be5a8172106e6a819a5