Increased the number of SES in the EventBasedPSHA demo [skip hazardlib][demos]
Increased the number of SES in the EventBasedPSHA demo [skip hazardlib][demos]


Former-commit-id: 7b21fe07261908359d0311f11607f4b6638726bf
gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine,gem/oq-engine