HAWQ-646. Bump up optimizer version number to 1.626
HAWQ-646. Bump up optimizer version number to 1.626

wengyanqing/incubator-hawq,wengyanqing/incubator-hawq,stanlyxiang/incubator-hawq,wengyanqing/incubator-hawq,huor/incubator-hawq,stanlyxiang/incubator-hawq,huor/incubator-hawq,outofmem0ry/incubator-hawq,wengyanqing/incubator-hawq,outofmem0ry/incubator-hawq,outofmem0ry/incubator-hawq,lavjain/incubator-hawq,jianlirong/incubator-hawq,outofmem0ry/incubator-hawq,lavjain/incubator-hawq,jianlirong/incubator-hawq,wengyanqing/incubator-hawq,stanlyxiang/incubator-hawq,wengyanqing/incubator-hawq,lavjain/incubator-hawq,lavjain/incubator-hawq,lavjain/incubator-hawq,jianlirong/incubator-hawq,stanlyxiang/incubator-hawq,wengyanqing/incubator-hawq,huor/incubator-hawq,outofmem0ry/incubator-hawq,outofmem0ry/incubator-hawq,huor/incubator-hawq,jianlirong/incubator-hawq,huor/incubator-hawq,jianlirong/incubator-hawq,stanlyxiang/incubator-hawq,lavjain/incubator-hawq,jianlirong/incubator-hawq,lavjain/incubator-hawq,lavjain/incubator-hawq,jianlirong/incubator-hawq,stanlyxiang/incubator-hawq,wengyanqing/incubator-hawq,outofmem0ry/incubator-hawq,jianlirong/incubator-hawq,outofmem0ry/incubator-hawq,huor/incubator-hawq,huor/incubator-hawq,stanlyxiang/incubator-hawq