SPIGOT-6034: World.getWorldFolder() includes the dot in the path

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

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

@@ -1881,7 +1881,7 @@ public class CraftWorld implements World {
 
     @Override
     public File getWorldFolder() {
-        return world.convertable.getWorldFolder(SavedFile.ROOT).toFile();
+        return world.convertable.getWorldFolder(SavedFile.ROOT).toFile().getParentFile();
     }
 
     @Override