Update git submodules

* Update docs/submodules/samplevnf from branch 'master'
  - common: Changes to common code for gateway support

    JIRA: SAMPLEVNF-58

    Common code changes for gateway packet forwarding.

    Change-Id: Ie002c94b8febab9c0923e1bb261e5ea931cd4712
    Signed-off-by: Anand B Jyoti <anand.b.jyoti@intel.com>

diff --git a/docs/submodules/samplevnf b/docs/submodules/samplevnf
index 88180c7..3ec8961 160000 (submodule)
--- a/docs/submodules/samplevnf
+++ b/docs/submodules/samplevnf
@@ -1 +1 @@
-Subproject commit 88180c786ad5a7f983e5868376b0db167fffc13c
+Subproject commit 3ec896179c547d54a18b40494a2871d7e328c0bf