Update git submodules

* Update docs/submodules/sdnvpn from branch 'stable/fraser'
  - Fixing invocation of Tempest tests

    Only 7 bgpvpn Tempest tests were run by the SDNVPN Tempest test instead
    of the full set of Tempest tests. This patch fixes and simplifies the
    invocation of bgpvpn Tempest tests.

    Change-Id: I1b207ea3da27dd43ab034b84f81992a5e0be2ec1
    Signed-off-by: Georg Kunz <georg.kunz@ericsson.com>
    (cherry picked from commit 2b8d01a7f79b0d3903964827be56347dc83d5591)

diff --git a/docs/submodules/sdnvpn b/docs/submodules/sdnvpn
index 5a48bbc..e617bed 160000 (submodule)
--- a/docs/submodules/sdnvpn
+++ b/docs/submodules/sdnvpn
@@ -1 +1 @@
-Subproject commit 5a48bbcdee0b1900ef6ab0618006600104fbfb07
+Subproject commit e617beda206166f291433f58081e48ac50e48dbb