set convert_indent_on_save to true

https://github.com/godotengine/godot/issues/30324

editor/editor_settings.cpp

@@ -436,7 +436,7 @@ void EditorSettings::_load_defaults(Ref<ConfigFile> p_extra_config) {
 	_initial_set("text_editor/indent/size", 4);
 	hints["text_editor/indent/size"] = PropertyInfo(Variant::INT, "text_editor/indent/size", PROPERTY_HINT_RANGE, "1, 64, 1"); // size of 0 crashes.
 	_initial_set("text_editor/indent/auto_indent", true);
-	_initial_set("text_editor/indent/convert_indent_on_save", false);
+	_initial_set("text_editor/indent/convert_indent_on_save", true);
 	_initial_set("text_editor/indent/draw_tabs", true);
 	_initial_set("text_editor/indent/draw_spaces", false);