geoprocessing service returning a URL with two hostnames

[greggerzj]

I have a python geoprocessing service that is running ArcGIS for Server 10.1
SP1 that zips up a file geodatabase. The GP service's output parameter data type
is set to File.

The issue happens when we have a proxy server handling requests from the
internet. We get a result from the GP service that looks like the following:

{
"paramName": "outFile",
"dataType": "GPDataFile",
"value": {"url": "http://<external host>, <internal host>/arcgis/rest/directories/arcgisjobs/exportasync_gpserver/j1135e0619f424d6e886c1bb617ec5342/scratch/outGdb.zip"}
}

Is there a setting within Server at 10.1 that I can change to get around having
both hostnames in the result url or will I need to code around this? I should
mention that this wasn't an issue at 10.0 SP3.