egamma-calib-wtots1Syst

Change computation of wstot1 systematics: Instead of using pre-stored values at Et=40 GeV, recompute these values from the fitted parameters for Et=40 GeV, such that this systematics is 0 at 40 GeV as it should for this kind of extrapolation systematics. Due to the accuracy of the fit, it was not completely the case before with up to few 10**-4 "spurious" systematics in the endcap (much less in the barrel)