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


Former-commit-id: 7d84d67cecb57090acb50623d6faae46eed6c18f [formerly b71eee2a1d164a2c3d27cdbfa3046e8d36ae150d] [formerly b71eee2a1d164a2c3d27cdbfa3046e8d36ae150d [formerly 5b09da696243da2ece3d1bf3883980022f3c9df9]]
Former-commit-id: f2687e8ef4a946dfc913e5b95faa208d9c995a42
Former-commit-id: ee4fb67acd829191564d47140880a1ccccf200cb
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine