Update git submodules

Update git submodules

* Update docs/submodules/functest from branch 'stable/euphrates'
  - Fix userdata issue for vping and orchestra

    1. When creating VM, the type of the param userdata should be str, to
       conform with that in snaps [1].
    2. Remove the infinite loop for vping in userdata
    3. Fix the criteria for vping_userdata and vping_ssh

    [1]: https://git.opnfv.org/snaps/tree/snaps/openstack/utils/nova_utils.py#n92

    Change-Id: I262a7ebb93ec90bb6f8f3acb5d564f210abcfc4b
    Signed-off-by: Linda Wang <wangwulin@huawei.com>
    (cherry picked from commit 5a24cb4a7db33e693a063f5c2a66406283aa5cfb)