nautilus-autorun: don't remember start_app unless app was chosen

media_autorun_x_content_open_folder overrules
media_autorun_x_content_start_app, but adding a content type to both lists
looks confusing.

diff --git a/libnautilus-private/nautilus-autorun.c b/libnautilus-private/nautilus-autorun.c
--- a/libnautilus-private/nautilus-autorun.c
+++ b/libnautilus-private/nautilus-autorun.c
@@ -787,7 +787,7 @@
 
 		if (data->remember) {
 			/* make sure we don't ask again */
-			nautilus_autorun_set_preferences (data->x_content_type, TRUE, data->selected_ignore, data->selected_open_folder);
+			nautilus_autorun_set_preferences (data->x_content_type, data->selected_app != NULL, data->selected_ignore, data->selected_open_folder);
 			if (!data->selected_ignore && !data->selected_open_folder && data->selected_app != NULL) {
 				g_app_info_set_as_default_for_type (data->selected_app,
 								    data->x_content_type,
