HAWQ-1356. Add waring when user does not have usage privilege of namespace.
HAWQ-1356. Add waring when user does not have usage privilege of namespace.

Signed-off-by: Hubert Zhang <c390d83fb437a9b3d934f0f0ecaa2e66f2bc6e0f@apache.org>

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