Update git submodules

Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Merge "[jump] Add simple check for required Linux bridges"
  - [jump] Add simple check for required Linux bridges

    - MaaS requires PXE/admin to be a Linux bridge;
    - if virtual nodes are present, they should be hooked to a proper
      Linux bridge for the Public network, but only throw a warning if
      not (and create a mock public virsh network instead);
    - if both virtual and baremetal nodes are present, Public bridge is
      indirectly mandatory (we can't mock it);

    JIRA: FUEL-339

    Change-Id: Idfe99d66c49eadc56cb3d94ca4db3467fb76d388
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>