Update git submodules

* Update docs/submodules/sdnvpn from branch 'master'
  - Add suport for fuel installer

    JIRA: FUEL-393

    This patch adds support for fuel installer by modifying relevant
    pieces of code.

    Change-Id: I5245e84022dd258c96648b0985660e093ca98b52
    Signed-off-by: Stamatis Katsaounis <mokats@intracom-telecom.com>

diff --git a/docs/submodules/sdnvpn b/docs/submodules/sdnvpn
index 2a58426..b17b3d8 160000 (submodule)
--- a/docs/submodules/sdnvpn
+++ b/docs/submodules/sdnvpn
@@ -1 +1 @@
-Subproject commit 2a584266524ace3cbcd8e906e971726706eb5ce5
+Subproject commit b17b3d80849b9c9989fb4deeb6001a6ff78261c1