Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Merge "https enabled checking"
  - https enabled checking

    JIRA: DOVETAIL-456

    before to check OS_CACERT and OS_INSECURE when using
    https + credential or + no credential,
    there's a need to check if https enabled.
    error log
    https://build.opnfv.org/ci/view/dovetail/job/dovetail-fuel-baremetal-proposed_tests-danube/37/console

    Change-Id: Icdf17541fe6cf64b2f000d424c8d4dcc28cfd371
    Signed-off-by: MatthewLi <matthew.lijun@huawei.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index c3e1d8c..6ddd0a9 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit c3e1d8cb6bb228058a152fdcdbd8dec0d2457748
+Subproject commit 6ddd0a92a137906ae0dd00468c5db556dda91555