Fix scenario_risk test

This is breaking the current master: https://ci.openquake.org/job/master_oq-engine/1463/
The expected numbers are different because there is an asset more and the gmvs (computed from the exposure) are different.
Tests running here: https://ci.openquake.org/job/zdevel_oq-engine/934
I propose to keep indentation as it was in the old version