fix(xtintin): minor bug

plugins/lib/xtintin/funcs.tin

@@ -79,7 +79,7 @@ PaoTin++ © 2020~2022 的所有版权均由担子炮(dzp <danzipao@gmail.com>)
     #local restricted   {%2};
 
     #if { "$dir" == "" } {
-        #return "";
+        #return {};
     };
 
     #local entry ${xtt.dir.table[$dir]};