Description: Some cities I founded - after ransacking another player's outpost on the same tile - never displayed their graphic on the map (as outpost or as a city later)

Steps to reproduce: 1. Ransack an opponent's outpost 2. Build an outpost on the tile 3. Create a city

Reproducibility: ??
Expected Behaviour: Seeing the city/outpost on the map
Actual Behaviour: No graphic displayed.