Changed compute_gmfs to not return the useless ruptures [skip hazardlib]
Changed compute_gmfs to not return the useless ruptures [skip hazardlib]


Former-commit-id: c61200454aa8eadf8f331b80e81bbc7f909bd861
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine