Fix changing town zone settings not updating town zone radii

This could cause MP desyncs

src/town.h

@@ -271,6 +271,7 @@ void ResetHouses();
 void ClearTownHouse(Town *t, TileIndex tile);
 void UpdateTownMaxPass(Town *t);
 void UpdateTownRadius(Town *t);
+void UpdateTownRadii();
 CommandCost CheckIfAuthorityAllowsNewStation(TileIndex tile, DoCommandFlag flags);
 Town *ClosestTownFromTile(TileIndex tile, uint threshold);
 void ChangeTownRating(Town *t, int add, int max, DoCommandFlag flags);