Starting map zoom level on old worlds is not 16 chunks by 16 chunks

The bug

When you create a new old type world with a starting map, you will get the wrong map size when you create the map. The map is supposed to be 16 chunks by 16 chunks(Level 1/4), but instead you get a map that is 128 by 128 chunks(Level 4/4). 

Steps to reproduce

1. Create a new world with a starting map and the world type at old.
2. Create the map once you spawn into your world
3. The map you get is not the correct size