minor bug fix in os detection
minor bug fix in os detection


Former-commit-id: d82fe32759ee94f03ec1cdf692ae258d629f0a47 [formerly d82fe32759ee94f03ec1cdf692ae258d629f0a47 [formerly 814b63300abb936eaf640e3f76b767425b2c0a1a]]
Former-commit-id: 73e1ad53f397f305b000d752ceca486e7cd338d0
Former-commit-id: 0fcdc1ae737564b25e2ab6ddfc55c52c2e234bbd
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine