update

Signed-off-by: Nzengyawen <zengyawen1@huawei.com>

zh-cn/application-dev/media/camera-preformance-imporvement.md

@@ -99,15 +99,15 @@ boolean isSupported = this.photoOutPut.isQuickThumbnailSupported()
 if (isSupported) {
     // 使能快速缩略图
     this.photoOutPut.enableQuickThumbnail(true)
-}
-this.photoOutPut.on('quickThumbnail', (err, pixelmap) => {
+    this.photoOutPut.on('quickThumbnail', (err, pixelmap) => {
     if (err || pixelmap === undefined) {
         Logger.error(this.tag, 'photoOutPut on thumbnail failed ')
         return
     }
     // 显示或保存pixelmap
     this.showOrSavePicture(pixelmap)
-})
+  })
+}
 ```
 
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