fix: return null if reference is null

core/src/main/java/mc/core/Location.java

@@ -99,7 +99,7 @@ public class Location implements Serializable{
 
     public World getWorld () {
         if (world == null) {
-            throw new IllegalStateException("World is not initialized");
+           return null;
         }
         if (world.get() == null) {
             throw new ResourceUnloadedException("You're trying to get unloaded world");