Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Merge "Bugfix: KeyError when Functest fails to store results into file"
  - Bugfix: KeyError when Functest fails to store results into file

    JIRA: DOVETAIL-445

    https://build.opnfv.org/ci/view/dovetail/job/dovetail-fuel-baremetal-proposed_tests-danube/19/console

    Change-Id: If933156bb3931e7bfc8ec31eb03ca5a3cb0bf8b0
    Signed-off-by: xudan <xudan16@huawei.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index 2a41e07..3d64e6a 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit 2a41e07a0cf9585a88bf6f593ac6fba1d284c7ec
+Subproject commit 3d64e6a44e1eb9a1664bf0594e4cb6b72912e726