Allow ns3 for 7.8.4 testing
It looks like the WSDL namespace definition changed from 7.8.4 to 7.10. 7.10 has http://dataobjects.soap.admin.openexchange.com/xsd as ns6 whereas 7.8.4 has it as ns3. To be able to test legacy 7.8.4 customers (altice, cox) we would need change the hardcoded value in the helpers.