NEC plugin: Bump L3RPC callback version to 1.1

update_floatingip_statuses RPC call implemented in Icehouse expects
RPC version 1.1 and RPC version of L3RpcCallback of other plugins
was bumped to 1.1, but the version of L3RpcCallback in NEC plugin
was not bumped to 1.1 yet.

Change-Id: I0073a3de9ea0cd59d43c821f9bdaea89bd125a65
Closes-Bug: #1323769
(cherry picked from commit e588ee5b470bdca25abc634db3144d2aa9b84554)