Fix signed/unsigned comparison warning in Control::WordWrapText
Fix signed/unsigned comparison warning in Control::WordWrapText

Font->GetEstimateCharacters should never return a negative value

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