message: Unbuildable units are not displayed in upgrade chart
diff: @@ -186,6 +186,8 @@ class UnitUpgradesGraph:
  unit = self.getUnitNumber(k)
  if (unit == -1):
  continue
  + if (gc.getUnitInfo(unit).isGraphicalOnly()):
  + continue
  if (self.getUnitType(unit) not in self.exceptionList):
  graph[unit] = Node()
  