Fix the building issue when protobuf is enabled.

Fu Juntang

2021-09-01 387fe1dbfffdc3d73cf46f2c054f4d25543c8523

1
2
3
4
5
ipcrm -a
 
./dgram_mod_req_rep server 2 & node0=$! && sleep 1
./dgram_mod_req_rep client 2 node1
kill $node0