Fix call to Core::Time::sleep for g++ 4.9
Fix call to Core::Time::sleep for g++ 4.9

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