Improve changelog [skip ci]
Improve changelog [skip ci]


Former-commit-id: 2a20a38667c3f921c7767f80bbe63ef8fedd1651 [formerly d6ecd38d5532394d93d7b06f75f47a149e5ba7e7]
Former-commit-id: 4ec4344b1db83e9ed6045b4e8594955fcf92fde5
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine