Core/Creatures: Set melee sheath as default only for creatures that do not have creature_addon data

src/server/game/Entities/Creature/Creature.cpp

@@ -357,8 +357,9 @@ bool Creature::UpdateEntry(uint32 Entry, uint32 team, const CreatureData* data)
 
     m_regenHealth = cInfo->RegenHealth;
 
-    // creatures always have melee weapon ready if any
-    SetSheath(SHEATH_STATE_MELEE);
+    // creatures always have melee weapon ready if any unless specified otherwise
+    if (!GetCreatureAddon())
+        SetSheath(SHEATH_STATE_MELEE);
 
     SelectLevel(GetCreatureTemplate());
     if (team == HORDE)