Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Adding SDNVPN tempest test cases to proposed_tests suite

    Adding the SDNVPN Tempest API test cases of the SDNVPN project to the
    proposed_tests suite to allow for running these tests in the CI pipeline for
    validating their suitability for inclusion in the OVP Euphrates release.

    JIRA: DOVETAIL-608

    Change-Id: Ic12db1584a2540a14979094c65fc128c6020ecea
    Signed-off-by: Georg Kunz <georg.kunz@ericsson.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index bcfc516..c308b9a 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit bcfc516053569199b87cb6e2a92456fcac50b1a2
+Subproject commit c308b9a718b8b4fc5e781f8d2a6dbe714e381834