SPIGOT-1768: Fix Eye of Ender with custom world generators.

By: md_5 <git@md-5.net>

paper-server/src/main/java/org/bukkit/craftbukkit/generator/CustomChunkGenerator.java

@@ -229,7 +229,7 @@ public class CustomChunkGenerator extends InternalChunkGenerator {
     public void recreateStructures(int i, int j) {}
 
     @Override
-    public void recreateStructures(Chunk chunk, int i, int i1) {
-
+    public void recreateStructures(Chunk chunk, int i, int j) {
+        strongholdGen.a(this.world, i, j, (ChunkSnapshot) null);
     }
 }