Update git submodules

* Update docs/submodules/sdnvpn from branch 'stable/danube'
  - Remove dependence inet

    A new ubuntu image with quagga included was uploaded to
    artifacts.opnfv.org/sdnvpn/
    ubuntu-16.04-server-cloudimg-amd64-disk1.img

    Change-Id: I7e48ebbc2b00b7e771f43b26303acc66c2c48457
    Signed-off-by: Nikolas Hermanns <nikolas.hermanns@ericsson.com>
    (cherry picked from commit 9e47ddb9739bb3e6b2ca91615c71bcd94c954172)

diff --git a/docs/submodules/sdnvpn b/docs/submodules/sdnvpn
index 6b2a7d1..7005583 160000 (submodule)
--- a/docs/submodules/sdnvpn
+++ b/docs/submodules/sdnvpn
@@ -1 +1 @@
-Subproject commit 6b2a7d15d61e76da0bbaf5f60134119fd9b23cbe
+Subproject commit 70055839b7e69e7cb02681c98c11f905331a1a4f