asp.net RewritePath重定向HTTP头Content-Location暴露真实路径解决方法

ASP.NET使用RewritePath重定向后，服务器响应的HTTP头会多个Content-Location：

HTTP/1.1 200 OK
Content-Length: 48150
Content-Type: image/jpeg
Content-Location: http://www.mzwu.com/test.jpg
Last-Modified: Tue, 18 Dec 2012 15:01:50 GMT
Accept-Ranges: bytes
ETag: "e119ee9b30ddcd1:1c48"
Server: Microsoft-IIS/6.0
X-Powered-By: ASP.NET
Date: Mon, 08 Sep 2014 01:29:40 GMT

Content-Location值为重定向文件的真实路径，在一些场合下我们不想让客户端知道这个路径，有办法去掉它吗？去不掉，但可以手工在IIS中给网站设置一个同名HTTP头借以隐藏真实路径：

现在效果如下

HTTP/1.1 200 OK
Content-Length: 48150
Content-Type: image/jpeg
Content-Location: mzwu.com
Last-Modified: Tue, 18 Dec 2012 15:01:50 GMT
Accept-Ranges: bytes
ETag: "e119ee9b30ddcd1:1c58"
Server: Microsoft-IIS/6.0
X-Powered-By: ASP.NET
Date: Mon, 08 Sep 2014 01:42:50 GMT