Update git submodules

Update git submodules

* Update docs/submodules/compass4nfv from branch 'stable/danube'
  - Merge "Switch off congress role in ansible plabook" into stable/danube
  - Switch off congress role in ansible plabook

    Installation often failed when creating user, role and service of congress.
    So we switch off congress here. If compass users want to use congress,
    just switch on congress in the ansible playbook.

    Change-Id: I6f75ec7d86582650adbb7b273810a0961e8361c8
    Signed-off-by: Yifei Xue <xueyifei@huawei.com>