As of Gateway 10.1 CR1 we are now seeing the following headers on responses back to the gateway:
Gateway 10.1 Cr1+
With gateway 10.1 CR1 the library used for http was upgraded. This library now uses a default behavior to add the Keep-Alive and Connection response headers.
You can modify this by setting the following property on the listen port:
Policy Manager->Tasks->Transports->Manage Listen Ports->Choose the port in question and select 'Properties'->Select the 'Advanced' tab and add the following property:
Property Name: useKeepAliveResponseHeader
You need to connect to policy manager on a different port from the port you are looking to update. So for instance, if you need to modify port 8443, then connect to policy manager initially on port 9443 and you will then be able to update the 8443 listen port.