TrackEff DownMuon overtime 'fix'

This line takes longer due to the need of reconstructing DownMuon tracks in the stripping line. Small change in seed P and PT was made (1500=>0 MeV and 0=>200 MeV)

Tested on the first DST sample, maximal times decreased from 12 and 18 seconds to 0.6 and 14 seconds, log below.

TimingAuditor.TIMER              INFO          StrippingTrackEffDownMuonLine1                     |    12.203 |    12.327 |    0.045    1252.4    44.85 |   10000 |   123.271 |
TimingAuditor.TIMER              INFO          StrippingTrackEffDownMuonLine2                     |    13.052 |    13.461 |    0.032   18111.3   186.74 |   10000 |   134.618 |

TimingAuditor.TIMER              INFO          StrippingTrackEffDownMuonLine1                     |    11.861 |    11.976 |    0.045     644.7    42.43 |   10000 |   119.763 |
TimingAuditor.TIMER              INFO          StrippingTrackEffDownMuonLine2                     |    12.669 |    12.803 |    0.035   14587.7   152.51 |   10000 |   128.032 |