TTAnalysis::Lepton stores charge as unsigned integer

[pieterdavid]

See https://github.com/cp3-llbb/TTAnalysis/blob/master/interface/Types.h#L70 and https://github.com/cp3-llbb/TTAnalysis/blob/master/interface/Types.h#L43 - probably just a typo or copy&paste error, and not an urgent problem, but I let you know just in case

[swertz]

Most definitely a typo, thanks! Always good to have a 3rd person proof reading the code XD