Update git submodules

Update git submodules

* Update docs/submodules/vswitchperf from branch 'master'
  - Merge "ci: Fix VPP back2back TCs"
  - ci: Fix VPP back2back TCs

    There was a generic issue with restoration of original environment
    after execution of testcase. Thus in case that multiple tests were
    executed, their settings could be corrupted. This issue was detected
    after VPP testcases were added into VSPERF DAILY CI job.

    There were two issues:

    * setttings.load_from_dict() method was used to restore original
      configuration values; However this method updates dict content
      with supplied values. If TC has introduced new dict item,
      then it was not removed from settings after TC execution
      and modified settings was applied also for next test(s).
    * test configuration passed to testcase constructor is used
      for initialization of TC members, which are later updated;
      As python does shallow copy on dict members by default,
      modification of such testcase members led to corruption
      of configuration of other testcases. Thus deepcopy of testcase
      configuration was introduced into vsperf constructor to
      avoid TC configuration corruption.

    JIRA: VSPERF-511

    Change-Id: I45fb49d48743015353652de12db4692333043733
    Signed-off-by: Martin Klozik <martinx.klozik@intel.com>
    Reviewed-by: Al Morton <acmorton@att.com>
    Reviewed-by: Christian Trautman <ctrautma@redhat.com>
    Reviewed-by: Sridhar Rao <sridhar.rao@spirent.com>
    Reviewed-by: Trevor Cooper <trevor.cooper@intel.com>