Update git submodules

* Update docs/submodules/dovetail from branch 'master'
  to 7d4456beaf190bbd6bb935325cfe43a1df1c70f2
  - Update OVP Support Email Address

    As the portals have moved from the opnfv.org domain to lfnetworking.org,
    the support address has changed as well from 'verified' to
    'ovp-support'.

    Change-Id: I341093992e456ac90580b3b96206a402f98bf2d2
    Signed-off-by: Trevor Bramwell <tbramwell@linuxfoundation.org>

diff --git a/docs/submodules/dovetail b/docs/submodules/dovetail
index 7360cbb..7d4456b 160000 (submodule)
--- a/docs/submodules/dovetail
+++ b/docs/submodules/dovetail
@@ -1 +1 @@
-Subproject commit 7360cbb9d286d8fac22947ab918a7285fea9d570
+Subproject commit 7d4456beaf190bbd6bb935325cfe43a1df1c70f2