Update git submodules

Update git submodules

* Update docs/submodules/fuel from branch 'stable/euphrates'
  - Workaround VCP minions timeout post pkg.upgrade

    pkg.upgrade was enabled for all salt minions, including VCP VMs,
    which take longer to perform the operation, probably due to an
    older set of packages in the Ubuntu disk image we use.
    One way to work around this is to switch to UCA Xenial image, and
    let Salt pre-provising salt minion on it, but that adds deploy
    time delay and has caused issues in the past (should be ok now).

    Alternatively, we can retry the pkg.upgrade until all minions
    respond, before moving on with the state execution. This prevents
    silently skipping the next salt calls (e.g. installing keepalived).

    Note that the issue did not manifest for OVD-DPDK, where after
    pkg.upgrade, DPDK is installed, giving VCP VMs enough time to return.

    While at it, retry 'salt.control' state apply too (non-critical,
    but it fails every once in a while).

    Fixes: 87310fb

    Change-Id: I97acc2b23206a55d72f7e6583ca42127fdbacc16
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
    (cherry picked from commit a6feb158fa5bc16b8d496c785c461c73ca715322)