Better Error Message From ShipStream Server in update_ip

[kiatng]

I had a typo in the API key username in login.xml:

kiatng@win10:~/shipstream/middleware$ bin/mwrun ShipStream_Test update_ip
Creating middleware_cli_run ... done
Exception: (2) Access denied.

At first I thought it was file permissions, but later found out it was a typo in the user name. A better error message would help identify the issue:

Exception in JSON-RPC server: (2) Access denied.