Remove unused import.
Remove unused import.


Former-commit-id: b19aabfa900e746e3c2180981b589f71bcbd76dd [formerly 95954e3368bb00985601d8cf5d2b205c7b637fbe]
Former-commit-id: a40b589cbc1af70eda12bd9eb4bb0aaf07e4cc34
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine