fix error

Author: justinlguo

sample/getBlindWatermark.php

@@ -38,7 +38,7 @@
     $result = $cosClient->ImageProcess(array(
         'Bucket' => 'examplebucket-1250000000', //存储桶名称，由BucketName-Appid 组成，可以在COS控制台查看 https://console.cloud.tencent.com/cos5/bucket
         'Key' => 'exampleobject',
-        'PicOperations' => $picOperations->queryString(),
+        'PicOperations' => $picOperationsTemplate->queryString(),
     ));
     // 请求成功
     print_r($result);