Have you tried to override the location (based on a constant) in your webservice call?
Changing the WSDL solved my problem!
I think a configuration change in SAP will prevent me to change the WSDL!
http://scn.sap.com/community/pi-and-soa-middleware/blog/2010/03/19/wsdl-wspolicy--what-is-it-und-how-can-i-get-rid-of-it-in-pi
Your wsdl is referencing a ws-policy. If you look at the policy details you'll see a reference to an artifact: <sp:httpstoken>
Having the artifact HttpsToken enforces with the wsdl that you can only use the service through an https connection (and some other requirements).
As the url to your SAP instructs a workaround is to disable the ws-policy in SAP. This will basically change the wsdl so that the policy is no longer specified, allowing the Mx app to setup the connection over an http connection.
I don't have experience with these settings in SAP, so I'm unsure if SAP also enforces this strictly on their end. You could try and manually alter the wsdl and remove the references to the policy (just remove the policy elements from the binding).
However a better solution would be to follow or change the policy.