Fixed race condition in datastore.set_attrs [skip hazardlib]
Fixed race condition in datastore.set_attrs [skip hazardlib]


Former-commit-id: 387087424a3d3633920bff5a3f2342ff0e7f66bf [formerly 18f09b7c772a1759f6da3bdc9f7354c171883730] [formerly 18f09b7c772a1759f6da3bdc9f7354c171883730 [formerly 12a2d7da479872322f64e61f3f0c0a8804251a72]]
Former-commit-id: 4cebfee5eae2d0957c46be560063fb0e9f9aaf7c
Former-commit-id: 440b2869a14a7b48a62d4099f9fdde8eb3012437
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine