Clean up remaining Flight.from_cp users.

The preferred API for this has been `Flight.departure` for a while.

qt_ui/widgets/ato.py

@@ -51,7 +51,7 @@ class FlightDelegate(TwoColumnRowDelegate):
             clients = self.num_clients(index)
             return f"Player Slots: {clients}" if clients else ""
         elif (row, column) == (1, 0):
-            origin = flight.from_cp.name
+            origin = flight.departure.name
             if flight.arrival != flight.departure:
                 return f"From {origin} to {flight.arrival.name}"
             return f"From {origin}"