Changed the npz exporter
Changed the npz exporter


Former-commit-id: 462b0c58cc5560826aa55bf095acb0eecb47f20b [formerly b8261af1452b959aeda67c292faa490526857180]
Former-commit-id: 7fc0fbd3b9522164273bfcd0ebe7998dc2412894
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine