Remove unnecessary set init I missed in last

Spigot-Server-Patches/Implement-an-API-for-CanPlaceOn-and-CanDestroy-NBT-v.patch

@@ -32,7 +32,7 @@ index 8e8390282..f52936581 100644
          this.s = this::l;
          if (this.i.canRead() && this.i.peek() == '#') {
 diff --git a/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java b/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java
-index eaf4cd11c..dc417fb9d 100644
+index eaf4cd11c..be2e736eb 100644
 --- a/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java
 +++ b/src/main/java/org/bukkit/craftbukkit/inventory/CraftMetaItem.java
 @@ -0,0 +0,0 @@ import javax.annotation.Nullable;
@@ -92,7 +92,6 @@ index eaf4cd11c..dc417fb9d 100644
          }
 +        // Paper start - Implement an API for CanPlaceOn and CanDestroy NBT values
 +        if (tag.hasKey(CAN_DESTROY.NBT)) {
-+            this.destroyableKeys = Sets.newHashSet();
 +            NBTTagList list = tag.getList(CAN_DESTROY.NBT, CraftMagicNumbers.NBT.TAG_STRING);
 +            for (int i = 0; i < list.size(); i++) {
 +                Namespaced namespaced = this.deserializeNamespaced(list.getString(i));
@@ -139,7 +138,6 @@ index eaf4cd11c..dc417fb9d 100644
 +
 +        Iterable<?> canDestroySerialized = SerializableMeta.getObject(Iterable.class, map, CAN_DESTROY.BUKKIT, true);
 +        if (canDestroySerialized != null) {
-+            this.destroyableKeys = Sets.newHashSet();
 +            for (Object canDestroyElement : canDestroySerialized) {
 +                String canDestroyRaw = (String) canDestroyElement;
 +                Namespaced value = this.deserializeNamespaced(canDestroyRaw);