Update git submodules

* Update docs/submodules/sdnvpn from branch 'stable/fraser'
  - Wait for instance deletion

    JIRA: SDNVPN-222

    Confirm the deletion of instance in order to prevent its port
    existence when trying to delete relevant subnet in a later stage.

    Change-Id: Iace0fbbd90d50f05764ac09682caae59baba22fa
    Signed-off-by: Stamatis Katsaounis <mokats@intracom-telecom.com>
    (cherry picked from commit ea48239f99fdddd703bebb1727575f844c097702)

diff --git a/docs/submodules/sdnvpn b/docs/submodules/sdnvpn
index 490a2fd..9f606df 160000 (submodule)
--- a/docs/submodules/sdnvpn
+++ b/docs/submodules/sdnvpn
@@ -1 +1 @@
-Subproject commit 490a2fde01b667e4a2a9133ab71cf026f1b9ba0e
+Subproject commit 9f606df245967e2a658b0cc75ba9b754175cbf21