Update git submodules

* Update docs/submodules/sdnvpn from branch 'stable/danube'
  - [docs] Adding apex deployment config guide

    JIRA: SDNVPN-171

    Change-Id: I076a087ab346e8e6e3063c958fefff657838b708
    Signed-off-by: Nikolas Hermanns <nikolas.hermanns@ericsson.com>
    (cherry picked from commit 38d1895faf9aaeefa6b64df6f4d149a00884b09b)

diff --git a/docs/submodules/sdnvpn b/docs/submodules/sdnvpn
index 05f2a54..abee279 160000 (submodule)
--- a/docs/submodules/sdnvpn
+++ b/docs/submodules/sdnvpn
@@ -1 +1 @@
-Subproject commit 05f2a546505b643b0301517587680bf5d7e0936a
+Subproject commit abee27986806ca98dbd184ae1c50d7e01241514b