fix the compatibility
fix the compatibility

sshling/tcpcopy,u20024804/tcpcopy,ycaihua/tcpcopy,liviusATnetskope/second,horryq/tcpcopy,sshling/tcpcopy,ycaihua/tcpcopy,left2right/tcpcopy,liviusATnetskope/second,left2right/tcpcopy,wfxiang08/tcpcopy,horryq/tcpcopy,daodaoliang/tcpcopy,eliteYang/tcpcopy,u20024804/tcpcopy,wfxiang08/tcpcopy,caosiyang/tcpcopy,eliteYang/tcpcopy,daodaoliang/tcpcopy,caosiyang/tcpcopy