Pass Random of GetRandomAttack by reference.

src/Library/CreatureData/LearnableAttacks.hpp

@@ -33,7 +33,7 @@ namespace CreatureLib::Library {
 
         const List<const AttackData*>& GetAttacksForLevel(uint8_t level) const;
 
-        virtual const AttackData* GetRandomAttack(Arbutils::Random rand = Arbutils::Random()) const {
+        virtual const AttackData* GetRandomAttack(Arbutils::Random& rand) const {
             if (_distinctAttacks.empty()) {
                 return nullptr;
             }