Update git submodules

* Update docs/submodules/sdnvpn from branch 'stable/euphrates'
  - Merge "Inheritance from Feature class" into stable/euphrates
  - Inheritance from Feature class

    Change-Id: I81aa9582452ca43a4eab32ba34a640043c89043e
    Signed-off-by: Jose Lausuch <jalausuch@suse.com>
    (cherry picked from commit b8d1b8a5f1b8f7d400c82c4988b0d76e1416d34b)

diff --git a/docs/submodules/sdnvpn b/docs/submodules/sdnvpn
index 55ed0c7..df04735 160000 (submodule)
--- a/docs/submodules/sdnvpn
+++ b/docs/submodules/sdnvpn
@@ -1 +1 @@
-Subproject commit 55ed0c7bf86effb047d7d64a33cac8dd9d8490ab
+Subproject commit df047359248272e0fecf29a6b3a82fa906823640