Made the number of bins in oq plot_losses configurable [skip CI]
Made the number of bins in oq plot_losses configurable [skip CI]


Former-commit-id: 35d99562c56701dd2843406d568f5f5419b78cd7 [formerly 1ff11765a91e39dbff1e190d704ddcfb8bf704d2]
Former-commit-id: e6d5ecdbf74d673c1da83023dbba947d51019d78
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine