Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Merge "Remove some tempest test cases that are not too common"
  - Remove some tempest test cases that are not too common

    Change-Id: I2a19b9f3e6c44bedef5d3cb20f480405e4d6d5e2
    Signed-off-by: xudan <xudan16@huawei.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index e7cbbe1..a9a26b6 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit e7cbbe1f7a9a7e16407f6108c8df5f877175a5cd
+Subproject commit a9a26b6416092442e61c3dc39ea40e1174608570