Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  - Release notes for OVP 2018.08 release

    JIRA: DOVETAIL-700

    Change-Id: I6835a6d6987d8e45c85fab851304a455db3ab0d6
    Signed-off-by: dimitris.tsiolakis <dmts@intracom-telecom.com>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index e79f851..3d71b61 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit e79f851c5b804db5884be05a50bc3ae0abe222b4
+Subproject commit 3d71b619bc869a99ce8f755d36c358f6698aaffa