Updated openquake.sql uiapi.hazard_calculation gsim and number_of_ground_motion_fields can be null
Updated openquake.sql uiapi.hazard_calculation gsim and number_of_ground_motion_fields can be null


Former-commit-id: eaecdf6dc0aeaaa8dc2399db9fbc022a7ced91b9 [formerly eaecdf6dc0aeaaa8dc2399db9fbc022a7ced91b9 [formerly 8836266e9d645c4173722fb7b927370cfcc40038]]
Former-commit-id: 0f10d455def6c96b4418e40fb0ef40d9f28c63c1
Former-commit-id: a52b6037cbfcb68f20c083c4f140758bf202c406
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine