Update git submodules

* Update docs/submodules/sdnvpn from branch 'master'
  - comment setup quagga playbook

    In order to enable verify jobs in XCI for sdnvpn, commenting quagga
    install playbook until its upstream review
    (https://review.openstack.org/#/c/523907/) is merged

    Change-Id: Ibeded8fe458e826259f2fb1cf82843f018aa3648
    Signed-off-by: Periyasamy Palanisamy <periyasamy.palanisamy@ericsson.com>

diff --git a/docs/submodules/sdnvpn b/docs/submodules/sdnvpn
index 016b6d8..a459c11 160000 (submodule)
--- a/docs/submodules/sdnvpn
+++ b/docs/submodules/sdnvpn
@@ -1 +1 @@
-Subproject commit 016b6d88f287e5d709ef1e796b9d71a545d6c809
+Subproject commit a459c11cf7450a685aa72f6f73d7dc6a88e867dd