Update git submodules

Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Merge "[reclass] Ensure pxe_admin_address is set for all"
  - [reclass] Ensure pxe_admin_address is set for all

    Some nodes did not rely on the _param:pxe_admin_address internal
    reclass param, although all of them do have an IP address in the
    PXE/admin network segment.

    Ensure all nodes define this param, so we can query all nodes with:
    $ salt '*' pillar.item _param:pxe_admin_address

    JIRA: FUEL-394

    Change-Id: I7575934752c8b459c52af8a8c98c2b0327756428
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>