Update git submodules

* Update docs/submodules/sfc from branch 'master'
  - Remove custom tacker-client installation script

    In previous releases we used a custom tacker client
    because we also used a custom tacker.

    For the next release we migrate to the the upstream tacker
    so we don't need anymore the aforementioned installation script
    because now we support the upstream tacker client.

    Change-Id: I0c502426161bbeaaf2418823fe91c2025f1494a8
    Signed-off-by: Dimitrios Markou <mardim@intracom-telecom.com>

diff --git a/docs/submodules/sfc b/docs/submodules/sfc
index 7287446..0339379 160000 (submodule)
--- a/docs/submodules/sfc
+++ b/docs/submodules/sfc
@@ -1 +1 @@
-Subproject commit 7287446920ed8859a7de78eef4235367a48a7d78
+Subproject commit 0339379381aca3e0234125945c5dabbe895b5039