Fix on VulnerabilityFunction.sample, now the stddevs are passed [skip hazardlib]
Fix on VulnerabilityFunction.sample, now the stddevs are passed [skip hazardlib]


Former-commit-id: a8885c3fc85571b8f83011452f3b8ad9f4be22f6
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine