Update git submodules

* Update docs/submodules/sdnvpn from branch 'master'
  - Merge "Stop and start quagga when reinstalling"
  - Stop and start quagga when reinstalling

    Change-Id: Iba9a5980de0cbdf9c04bdd4dad704c12abb55048
    Signed-off-by: Nikolas Hermanns <nikolas.hermanns@ericsson.com>

diff --git a/docs/submodules/sdnvpn b/docs/submodules/sdnvpn
index 19ff281..180024b 160000 (submodule)
--- a/docs/submodules/sdnvpn
+++ b/docs/submodules/sdnvpn
@@ -1 +1 @@
-Subproject commit 19ff2816a46f1c4828ea104bbe0361e2d5b93ba5
+Subproject commit 180024bb19dcc52469db87bf92980674fa5f65c2