Small fix in make_html_report.add_duration
Small fix in make_html_report.add_duration


Former-commit-id: 2f14446994590d6e83636f96cc40438b8234f5bd [formerly 2f14446994590d6e83636f96cc40438b8234f5bd [formerly 6dfdfbf09dbc8e7ce6038ac7e9fcd59f1fa2b30f]]
Former-commit-id: c48c0f841d44d173a98b9258c79579e7f0745394
Former-commit-id: 765ef681e6b74f8d473d03b92bb7d24bae331410
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine