Make ASAP a checkbox and maintain ASAP on changes.

Fixes https://github.com/Khopa/dcs_liberation/issues/642

qt_ui/dialogs.py

@@ -60,7 +60,7 @@ class Dialog:
         """Opens the dialog to edit the given flight."""
         cls.edit_flight_dialog = QEditFlightDialog(
             cls.game_model,
-            package_model.package,
+            package_model,
             flight,
             parent=parent
         )