Fixed a docstring [skip CI]
Fixed a docstring [skip CI]


Former-commit-id: 0683bcf97bd9c9178f6aae39d7f50927aaea9701 [formerly 3f32aedb71d0650f5879a52f86162b0d0ebfa89b]
Former-commit-id: 74d7ea393a0838567fccb67f06185cfb840ff472
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine