Update git submodules

* Update docs/submodules/nfvbench from branch 'master'
  - Add support for multiple physnets for sr-iov

    Update config plugin config
    Add readable error message on exception

    Change-Id: Ie22de349582abc34d7e62570118022463f835d64
    Signed-off-by: ahothan <ahothan@cisco.com>

diff --git a/docs/submodules/nfvbench b/docs/submodules/nfvbench
index 0036098..2d66234 160000 (submodule)
--- a/docs/submodules/nfvbench
+++ b/docs/submodules/nfvbench
@@ -1 +1 @@
-Subproject commit 0036098e46e16c9ae5b795b108a5b9566c02906b
+Subproject commit 2d66234fe3b8b3e104e63218b5120a35ca400ea5