Update git submodules

* Update docs/submodules/sdnvpn from branch 'master'
  - Update networking-bgpvpn to 7.0.0

    networking-bgpvpn 7.0.0 was released for Pike [1]

    [1] https://docs.openstack.org/releasenotes/networking-bgpvpn/pike.html

    Change-Id: I4baf1810ee2390c71a0f4b831f11baedabc95360
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/sdnvpn b/docs/submodules/sdnvpn
index 349d25f..d429b73 160000 (submodule)
--- a/docs/submodules/sdnvpn
+++ b/docs/submodules/sdnvpn
@@ -1 +1 @@
-Subproject commit 349d25fb43e6a132edd80ce9c44a3982867eb0b7
+Subproject commit d429b734b32c183736a2578304c8ef73e44dcf5f