Fixes OOS ignore toggle in the save dialog.

Fixes bug #18330.

changelog

@@ -65,6 +65,7 @@ Version 1.9.9+svn:
      time
    * Slowed units are now tinted to be recognizable at a glance
    * Fixed: Removed old markup style from OOS messages (bug #18387).
+   * Fixed: OOS ignore toggle in the save dialog (bug #18330).
  * WML engine:
    * Readded the liminal alignment
    * Added four-difficulty versions of certain macros: QUANTITY4,

src/gui/dialogs/game_save.cpp

@@ -77,6 +77,9 @@ tgame_save_oos::tgame_save_oos(
 	register_label("txtFilename", false, filename);
 	register_label("lblMessage", true, message);
 	register_bool("ignore_all", true, ignore_all);
+
+	/* Always need the ignore_all flag. */
+	set_always_save_fields(true);
 }
 
 } // namespace gui2