Update git submodules

* Update docs/submodules/sdnvpn from branch 'master'
  - Host openstack utils in SDNVPN

    SDNVPN is the last project using the deprecated openstack utils which
    are being removed from Functest tree.

    All methods unused by SDNVPN could be safely removed in a second change.
    This patch aims at publishing them asis.

    Change-Id: I4e479e6def2c691799c9bd86ba325e3d1544ef0d
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/sdnvpn b/docs/submodules/sdnvpn
index 43b29ad..016b6d8 160000 (submodule)
--- a/docs/submodules/sdnvpn
+++ b/docs/submodules/sdnvpn
@@ -1 +1 @@
-Subproject commit 43b29ad7ed13cd9bbcc2316b3809ba64a45ea42d
+Subproject commit 016b6d88f287e5d709ef1e796b9d71a545d6c809