Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Minor docs change to test docs integration

    This is minor patch which updates the documentation in the dovetail
    repo in order to test the toolchain integration in opnfvdocs.

    Change-Id: Id91c57d1a38cf02d8ed4653bc9eddb7081f025e7
    Signed-off-by: Georg Kunz <georg.kunz@ericsson.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index 2713497..0df52c2 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit 27134971c6b7bf73573993d5cb6efeab78533200
+Subproject commit 0df52c2b1fe801b0f282c4f44aed7891a389d833