Move pT threshold of single electron line up to reduce rate

The current iteration of the unprescaled single electron line is using very high rates with unclear physics targets. This will move the pT threshold of the unprescaled line from 17.5 GeV to 24 GeV, and hopefully reduce the rate by ~35%.

Access to lower pT electrons is still available in the ISO line (down to 15 GeV) and the prescaled line (down to 10 GeV). This should be satisfactory for any unfolding/calibration studies, while staying un-prescaled for the target physics range of W decays.