Fix build: missing unistd.h include
Fix build: missing unistd.h include

dankenigsberg/logcabin,logcabin/logcabin,TigerZhang/logcabin,tempbottle/logcabin,chaozh/logcabin,logcabin/logcabin,chaozh/logcabin,dankenigsberg/logcabin,TigerZhang/logcabin,tempbottle/logcabin,chaozh/logcabin,TigerZhang/logcabin,dankenigsberg/logcabin,logcabin/logcabin,gaoning777/logcabin,gaoning777/logcabin,tempbottle/logcabin,gaoning777/logcabin,logcabin/logcabin,TigerZhang/logcabin,dankenigsberg/logcabin,tempbottle/logcabin,chaozh/logcabin,gaoning777/logcabin