Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - SDNVPN test cases failed in CI

    JIRA: DOVETAIL-439

    1. SDNVPN test cases run in CI failed, because the file
      /home/opnfv/repos/sdnvpn/sdnvpn/test/functest/config.yaml is empty.
    2. copy the file userconfig/sdnvpn_config_testcase1/2/4/8.yaml
      to /home/opnfv/repos/sdnvpn/sdnvpn/test/functest/config.yaml in Functest container

    Change-Id: Ie904f83c755efc0d9e0abe5dcd44fe4a5056123e
    Signed-off-by: xudan <xudan16@huawei.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index bd5ff3b..ed7de0f 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit bd5ff3bd10fffd84e79dad47be4d6fb7eea66d26
+Subproject commit ed7de0f59902094646ec53e0c3af192538833611