Fix Minimap for Custom Maps

[Flynn]

Currently the minimap is derped for all custom maps. The minimap is not clickable which means that it is almost pointless to zoom in on an area and therefore you end up nearly always zoomed out when playing.

[Eukanuba]

It's caused by the map not having the heightmap/cartographic information included correctly. I'm not sure if this is something that can be corrected after the fact, but if it is it would have to be done on a map by map basis and would be very time-consuming.