fixed 1ca45294 from https://gitee.com/ge-yafang/docs/pulls/12262

update zh-cn/application-dev/reference/apis/js-apis-wallpaper.md.
Signed-off-by: N葛亚芳 <geyafang@huawei.com>

zh-cn/application-dev/reference/apis/js-apis-wallpaper.md

@@ -642,7 +642,8 @@ restore(wallpaperType: WallpaperType): Promise<void>
 
 **示例：**
   
-```js wallpaper.restore(wallpaper.WallpaperType.WALLPAPER_SYSTEM).then((data) => {
+```js 
+wallpaper.restore(wallpaper.WallpaperType.WALLPAPER_SYSTEM).then((data) => {
     console.log(`success to restore.`);
   }).catch((error) => {
     console.error(`failed to restore because: ` + JSON.stringify(error));