mod_swift_sys.c: fix a bug about d_core (no reset after swift being restarted)
mod_swift_sys.c: fix a bug about d_core (no reset after swift being restarted)

kongjian/tsar,alibaba/tsar,alibaba/tsar,xdddyzxzjyqc/monitorhp,billychou/tsar,billychou/tsar,kongjian/tsar,xdddyzxzjyqc/monitorhp