Update git submodules

* Update docs/submodules/nfvbench from branch 'master'
  - Move docker build to 1.2.3

    Change-Id: Ic71b41027bf580c5110c0fe2fb3128eec77681cc
    Signed-off-by: ahothan <ahothan@cisco.com>

diff --git a/docs/submodules/nfvbench b/docs/submodules/nfvbench
index 5baff66..c8e84a1 160000 (submodule)
--- a/docs/submodules/nfvbench
+++ b/docs/submodules/nfvbench
@@ -1 +1 @@
-Subproject commit 5baff6620aee46376023b209c7d11c56a7c5181a
+Subproject commit c8e84a12843e2cab36ea4570095026b900345f1b