zmb does not handle IDN names correctly

[matsduf]

Zonemaster updated with #1132 support IDN names to the RPC API using curl, e.g. with the following command,

curl 'http://localhost:5000' --data '{"jsonrpc":"2.0","id":0,"method":"get_data_from_parent_zone","params":{"domain":"Råttgift.se"}}'

But that does not work if zmb is used:

zmb start_domain_test --domain råttgift | jq
{
  "id": 1,
  "error": {
    "data": [
      {
        "path": "/domain",
        "message": "Domain name has a non-ASCII label (\"råttgift\") which is not a valid U-label."
      }
    ],
    "code": "-32602",
    "message": "Invalid method parameter(s)."
  },
  "jsonrpc": "2.0"
}