Update git submodules

* Update docs/submodules/samplevnf from branch 'stable/euphrates'
  - UDP_Replay: changes for gateway packet forwarding

    JIRA: SAMPLEVNF-70

    Integrating gateway packet forwarding to UDP_Replay VNF.

    Change-Id: I00f2bc498563b81260c2c98275f7a73dbc2cb445
    Signed-off-by: Anand B Jyoti <anand.b.jyoti@intel.com>

diff --git a/docs/submodules/samplevnf b/docs/submodules/samplevnf
index b01d163..74c5414 160000 (submodule)
--- a/docs/submodules/samplevnf
+++ b/docs/submodules/samplevnf
@@ -1 +1 @@
-Subproject commit b01d1637049116bf45f0c072623be2aebe0e52fc
+Subproject commit 74c5414a1fc7bc2e72c8b727dea974643f3c1bbe