fix num_orders_as_shipping_address, num_orders_as_billing_address wrong description.
fix num_orders_as_shipping_address, num_orders_as_billing_address wrong description.

sasha0/django-oscar,django-oscar/django-oscar,sonofatailor/django-oscar,solarissmoke/django-oscar,solarissmoke/django-oscar,django-oscar/django-oscar,sasha0/django-oscar,sasha0/django-oscar,sasha0/django-oscar,solarissmoke/django-oscar,sonofatailor/django-oscar,sonofatailor/django-oscar,django-oscar/django-oscar,solarissmoke/django-oscar,sonofatailor/django-oscar,django-oscar/django-oscar