`--raw` is ignored when translating xh commands using `--curl`

[ducaale]

Expected

$ xh httpbin.org/post --raw=hello --curl
# Not sure if content-type should be set if body is invalid JSON
curl http://httpbin.org/post -H 'content-type: application/json' -H 'accept: application/json, */*;q=0.5' -d 'hello'

Actual

$ xh httpbin.org/post --raw=hello --curl
curl http://httpbin.org/post