Fix unsigned/signed comparison in UfopaediaCategory::EventOccurred
Fix unsigned/signed comparison in UfopaediaCategory::EventOccurred

FranciscoDA/OpenApoc,AndO3131/OpenApoc,AndO3131/OpenApoc,AndO3131/OpenApoc,pmprog/OpenApoc,ShadowDancer/OpenApoc,Istrebitel/OpenApoc,steveschnepp/OpenApoc,FranciscoDA/OpenApoc,steveschnepp/OpenApoc,FranciscoDA/OpenApoc,ShadowDancer/OpenApoc,pmprog/OpenApoc,Istrebitel/OpenApoc