Fixed a typo in docstring
Fixed a typo in docstring


Former-commit-id: ec7b6725ba99be092404a09ed99cf0b57cc4f5a3 [formerly dbbec58df5e776593e24a3c2a9392f94b83491fd]
Former-commit-id: ad561bb648e29d02ed0c2d1456f7f8d0e022c816
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine