Update utils/celery-status for Celery 4
Update utils/celery-status for Celery 4


Former-commit-id: dc6f2e71f705f2a6612ada9acbe6cde336ec30ef [formerly 8f27d3b48b7499cf1fb728c22ec3e7e9cfb956e5] [formerly 8f27d3b48b7499cf1fb728c22ec3e7e9cfb956e5 [formerly f9068b96d90c997d0ee0337dfd09d96a97715025]]
Former-commit-id: d94bea12647b5cda5507b24d7ba483091e34f4c5
Former-commit-id: 6128ee7593373f4cea245d66da34b2d2cdb57284
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine