Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Bugfix: Failed to get the hardware info

    The directory of userconfig has changed from
    /home/opnfv/dovetail/dovetail/userconfig to /etc/dovetail/userconfig.

    Change-Id: Id3e8b1f3e9299e9263a4adf3456b6733fdb62e11
    Signed-off-by: xudan <xudan16@huawei.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index 66d2046..3330fb6 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit 66d20467c423505559bba2efa5aae2619903d647
+Subproject commit 3330fb68a80794f8df503b2956a03f57613a601a