BPHY12 derivation: tightened selection.
This MR makes updates BPHY12 derivation. Following the offline-analysis base requirements, the cuts in the BPHY12 derivation are tightened. The size of the derivation format goes down by a factor of 2x. It is also possible that the tightening of the cuts would fix the crash on one data event mentioned in https://its.cern.ch/jira/browse/ATLBPHYS-193 (unfortunately, the problem is not locally reproducible, but is obviously triggered by too many candidates in the event).