Fix a bug in computing errors for efficiency for weighted events when eff+error >= 1 or eff-error <= 0. This fixes ROOT-6601
Fix a bug in computing errors for efficiency for weighted events when eff+error >= 1 or eff-error <= 0. This fixes ROOT-6601

tc3t/qoot,tc3t/qoot,tc3t/qoot,tc3t/qoot,tc3t/qoot,tc3t/qoot,tc3t/qoot,tc3t/qoot,tc3t/qoot,tc3t/qoot