fixes for ssWWHjj [skip modfiles]

Description of bug

ATLMCPROD-10816

grid job killed by huge CPU time, due to the mixed usage of nEventsPerJob and maxEvents previously

Changes introduced

replace all things with lines of:

safefactor = 1.1
evgenConfig.nEventsPerJob = 2000
nevents = safefactor * evgenConfig.nEventsPerJob 

Tests

Issues resolved

Closes #