Update git submodules

Update git submodules

* Update docs/submodules/releng-xci from branch 'master'
  - Merge "fix k8 aio flavor undefined variable"
  - fix k8 aio flavor undefined variable

    1. fix error that kube_require_packages is undefined
    2. add "remote_user: root" in configure-kubenet.yml
       if don't add this, it will have issue to connect host.
       fatal: [opnfv]:UNREACHABLE! => {"changed": false, "msg":
       "Failed to connect to thehost via ssh: Permission denied (publickey,password).\r\n",
       "unreachable": true"}

    installer-type:kubespray
    deploy-scenario:k8-nosdn-nofeature

    Change-Id: Ia8d1980ad18375c0cff3a97b284b0f53d7539e23
    Signed-off-by: wutianwei <wutianwei1@huawei.com>