remove redundant code and setting in TCP adaptor
- remove redundant code in TCP adaptor: e.g. useless integer member: sid.
- remove redundant setting in TCP adaptor, especially, redundant port id. In original code, num_threads * num_servers port ids are used. Actually, ipset has already indicated sid of receiver. In function port_code(dst_sid, dst_tid), dst_sid is not necessary.
Already tested by gtest in one machine and tested by lubm_40 (7 queries and emulator)