calcs/hazard/classical/core:
calcs/hazard/classical/core:

Classical calculator now uses the cached SiteCollection in tasks, instead
recomputing it every time.


Former-commit-id: c2f58e64a204a24d892b9e0ad0ac426d278e7a99
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine