Default to port 443 if UseSSL set.

[Integralist]

Problem: if --use-ssl flag is provided but no port is set, then we should default to port 443 and also warn the user about this behaviour if the --verbose flag is provided.

Notes: you can't set a port number as part of the address field (e.g. 127.0.0.1:443) as the API considers that invalid...

$ curl -s -H "Accept:application/vnd.api+json" -H "Fastly-Key: $FASTLY_API_KEY" -X PUT -d "address=127.0.0.1:443" https://api.fastly.com/service/4nE2aoohVrsds0OZGpSIP8/version/1/backend/httpbin | jq

{              
  "errors": [   
    {                     
      "detail": "Address 'address' is not a valid IPv4, IPv6 or hostname",
      "title": "Bad request"
    }                                                                                                                                                                                                                                         
  ]            
}   

[phamann]

Looks good to me other than minor nit around terminology in the verbose output. It would have been good to also have a test to actually assert 443 was set if no port was supplied, however that won't be possible until we refactor these command tests to mirror the patterns used in the logging endpoints.