Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Cosmetic cleanup of tempest test case lists

    There are some superflouos lines separating the list of tempest test
    cases. These are restructuring artifacts which can be deleted.

    Change-Id: I7b3474090fa3d7b1506d5a4f3dcd1b32dd68900a
    Signed-off-by: Georg Kunz <georg.kunz@ericsson.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index 4675432..7bfb981 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit 46754323aeac6193dd9b451a6525a478fdb0887b
+Subproject commit 7bfb98175b9b974902531a07800b6a80be9a8f8e