Fixed mistake introduced in !2665

Description of bug

In !2665 (merged) introduced nEventsPerJob_fromJO which was not necessary since the idea was to always overwrite nEventsPerJob from the JO whenever a JO defines it or set it to 10k if it does not define it, so that we always check what actually runs in ProdSys.

Changes introduced

Remove nEventsPerJob_fromJO and only keep nEventsPerJob

Tests

Before

After

Issues resolved

Closes #219 (closed)