Fix function Detector::getLocalPosition (follow-up on MR !116)
This fixes #74 (closed).
As described in the issue, the track residuals of the ATLASpix were shifted off zero after MR !116 (merged).
I found that this was due to the fact that we were previously calculating the local cluster position using
m_pitch.X() * (column - (m_nPixels.X()) / 2), m_pitch.Y() * (row - (m_nPixels.Y()) / 2), 0.);
After that MR, we're doing:
m_pitch.X() * (column - (m_nPixels.X()) / 2.), m_pitch.Y() * (row - (m_nPixels.Y()) / 2.), 0.);
so that in the former case we'd get
25/2 = 12 and now we're getting
25/2. = 12.5.