Fix strikeLightningEffect powers lightning rods and clears copper

paper-server/src/main/java/org/bukkit/craftbukkit/CraftWorld.java

@@ -723,7 +723,7 @@ public class CraftWorld extends CraftRegionAccessor implements World {
 
         LightningBolt lightning = EntityType.LIGHTNING_BOLT.create(this.world, EntitySpawnReason.COMMAND);
         lightning.moveTo(loc.getX(), loc.getY(), loc.getZ());
-        lightning.setVisualOnly(isVisual);
+        lightning.isEffect = isVisual; // Paper - Properly handle lightning effects api
         this.world.strikeLightning(lightning, LightningStrikeEvent.Cause.CUSTOM);
         return (LightningStrike) lightning.getBukkitEntity();
     }

paper-server/src/main/java/org/bukkit/craftbukkit/entity/CraftLightningStrike.java

@@ -13,7 +13,7 @@ public class CraftLightningStrike extends CraftEntity implements LightningStrike
 
     @Override
     public boolean isEffect() {
-        return this.getHandle().visualOnly;
+        return this.getHandle().isEffect; // Paper - Properly handle lightning effects api
     }
 
     public int getFlashes() {