Fix broken numbering in What's-new.md
Fix broken numbering in What's-new.md

Former-commit-id: ee9180660b1285aa539413994a9cc7596110d057 [formerly ef82e14311783157ab7650deea1112761cadb543]
Former-commit-id: adc04fb2c98a170f295bea733dd08d115d016907
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine