fix OffHandMult applying to shields
OffHandMult wasn't caring about o.special combat.
getObjectCombat returns o.special_combat if applicable, making check for T_STONESHIELD and o.subtype == "shield" superfluous.
OffHandMult wasn't caring about o.special combat.
getObjectCombat returns o.special_combat if applicable, making check for T_STONESHIELD and o.subtype == "shield" superfluous.