Update git submodules

Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Merge "Bugfix: sdnvpn test cases failed due to wrong module name"
  - Bugfix: sdnvpn test cases failed due to wrong module name

    SDNVPN test cases failed due to wrong module name.
    The module name needs to be changed into "sdnvpn.test.functest.testcase_1"
    Refer to patch https://gerrit.opnfv.org/gerrit/#/c/41385/
    Currently Dovetail uses functest:cvp.0.5.0 which uses module name "testcase_1".

    JIRA: DOVETAIL-510

    Change-Id: I3232760d3af34125c7da71a5d2c62ca32693c82b
    Signed-off-by: xudan <xudan16@huawei.com>