Update git submodules

Update git submodules

* Update docs/submodules/sfc from branch 'master'
  - Test the deletion of chain

    This is the flow of the test:

    1 - Create a vnffg in tacker (i.e. chain + classifier)
    2 - Remove the vnffg
    3 - Check that the RSPs are removed from operation DB in ODL and
    the classifier rules are not present in the flows
    4 - Create a new vnffg
    5 - Test the new chain:
      5.1 - Check HTTP traffic works
      5.2 - Block HTTP traffic in VNF and check that it does not work anymore

    Change-Id: Ia077e58c5cbce4258a2f8a36f6b961eb923ff9c5
    Signed-off-by: Manuel Buil <mbuil@suse.com>