Update git submodules

* Update docs/submodules/sdnvpn from branch 'master'
  - xci: Lowercase ansible variables

    Change-Id: I4aa8ca5f8fcd5626e4334fd1217930c065a1dc04
    Signed-off-by: Fatih Degirmenci <fdegir@gmail.com>

diff --git a/docs/submodules/sdnvpn b/docs/submodules/sdnvpn
index cc10bd4..fab5676 160000 (submodule)
--- a/docs/submodules/sdnvpn
+++ b/docs/submodules/sdnvpn
@@ -1 +1 @@
-Subproject commit cc10bd492affb033b68d3b8f4cb1d8c9d554f995
+Subproject commit fab5676180d3c00f0e71f89766a026f51a0cab8a