Update git submodules

* Update docs/submodules/sfc from branch 'master'
  - Adapt change in functest

    The variable TEST_DB_URL must be read as a env. variable since this patch":

    https://gerrit.opnfv.org/gerrit/#/c/49757/

    Change-Id: I8f77acbbb2fe949f5fbe8a3f983c49224d893bcc
    Signed-off-by: Manuel Buil <mbuil@suse.com>

diff --git a/docs/submodules/sfc b/docs/submodules/sfc
index d436faf..3f89ce1 160000 (submodule)
--- a/docs/submodules/sfc
+++ b/docs/submodules/sfc
@@ -1 +1 @@
-Subproject commit d436fafbde49d78e2e39a8a63c31747799531ca1
+Subproject commit 3f89ce129fb00647fa58bb273235ad3a2c8a0ba9