Properly save the new save safe setting, avoid crash.

editor/editor_node.cpp

@@ -4749,13 +4749,13 @@ EditorNode::EditorNode() {
 	scene_distraction = false;
 	script_distraction = false;
 
-	FileAccess::set_backup_save(EDITOR_DEF("filesystem/on_save/safe_save_on_backup_then_rename", true));
-
 	TranslationServer::get_singleton()->set_enabled(false);
 	// load settings
 	if (!EditorSettings::get_singleton())
 		EditorSettings::create();
 
+	FileAccess::set_backup_save(EDITOR_GET("filesystem/on_save/safe_save_on_backup_then_rename"));
+
 	{
 		int dpi_mode = EditorSettings::get_singleton()->get("interface/editor/hidpi_mode");
 		if (dpi_mode == 0) {

editor/editor_settings.cpp

@@ -513,6 +513,7 @@ void EditorSettings::_load_defaults(Ref<ConfigFile> p_extra_config) {
 	_initial_set("filesystem/resources/auto_reload_modified_images", true);
 
 	_initial_set("filesystem/import/automatic_reimport_on_sources_changed", true);
+	_initial_set("filesystem/on_save/safe_save_on_backup_then_rename", true);
 
 	if (p_extra_config.is_valid()) {