fixed a bug in FloatArrayField to allow null/None
fixed a bug in FloatArrayField to allow null/None


Former-commit-id: 1d4e0dbc3b15647bfff4e2daba308d99b581664f [formerly c2d756a5bdb77f0c7498db07bc78ad3fb1e05a00]
Former-commit-id: febd9e5c98b1ada16075535abe7fd9be8d7dc36e
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine