Update git submodules

* Update docs/submodules/sdnvpn from branch 'master'
  - Merge "Update Scenario description document for Gambia release"
  - Update Scenario description document for Gambia release

    JIRA: SDNVPN-227

    Change-Id: I916cd78d94ba49d84a334a3bae4cb09975a972df
    Signed-off-by: dimitris.tsiolakis <dmts@intracom-telecom.com>

diff --git a/docs/submodules/sdnvpn b/docs/submodules/sdnvpn
index 8641815..785fed1 160000 (submodule)
--- a/docs/submodules/sdnvpn
+++ b/docs/submodules/sdnvpn
@@ -1 +1 @@
-Subproject commit 8641815e160a5b339467f3d39fe7d21f4ab08212
+Subproject commit 785fed155091a3eeca81dd07c2d308145ef2d98d