Update git submodules

Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Merge "MaaS: Disable network discovery"
  - MaaS: Disable network discovery

    In case nodes are already powered on and have an IP in the same
    range as the new MaaS DHCP one (e.g. from a previous deploy),
    MaaS API will reject the subnet creation due to overlapping
    addresses. Try to work around this by disabling network discovery.

    Change-Id: I70a33c552bf38a7ccbc1bb7e90c21f424f082bc5
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>