NEC plugin: Fix nec-agent unexpected exit due to RPC exception
Changes nec-agent to catch RPC exceptions in the main
daemon loop. It fixes the following two bugs.
- nec-agent dies with RPC timeout in secgroup RPC
(Closes-Bug: #
1235106)
- port_added message can be dropped when RPC timeout occurs
(Closes-Bug: #
1235111). Moves exception catch from PluginApi
to the main daemon loop.
Change-Id: I12394b739fc35bff271543f4625c5e3152e534ae
(cherry picked from commit
3df505e448d38929c20721b22d81e47bf917af6a)