level editor: road does not change on character or theme change

[evemartin]

When playing Rapid Router with a character other than Van, the road should change to a dirt path instead. In the Level Editor, when a new character other than Van is selected, the road does not change.

Steps to reproduce:

1. open the Level Editor
2. add some roads to the Level Editor map
3. go to the Character tab and select a new character other than Van
4. notice that the road stays the same and does not change to a dirt path