version: add a comment to explain a choice
version: add a comment to explain a choice

Former-commit-id: 46b70ec2946e7050e33fc6c0bd1e30c401dcf3c0 [formerly 52a96361ff6b8927a05d738806557393897629dd]
Former-commit-id: ed5306443a129e19114931b5f4282463e69f2c34
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine