Fixed the scenario risk test by going back to a fixed block_size
Fixed the scenario risk test by going back to a fixed block_size


Former-commit-id: c204cf55e19e412811e9d6ba32ed271d56160002 [formerly 75557274ecf6d6ee547da1ae080b58eb58c73904]
Former-commit-id: 5493ec3ba688da3346ff170328fb6085f49a9ea8
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine