Small change: improved error message for Create shipping label endpoint

On Friday, December 19, we will deploy a minor change to the Create shipping label endpoint. This change improves the clarity of one of the error messages returned when label creation fails.

Previous error message:
Failed to create shipping label in LAMA for retailerId:

New error message:
Failed to create shipping label for retailerId:

The reference to the service LAMA has been removed to make the message clearer for partners.