Accept Content-Type as symbol results in scrubbed body

[cramt]

When the Content-Type header is provided as a symbol instead of a string the body of the request will be scrubbed as if the Content-Type was not set

headers: {
  "Content-Type" => "application/json" # behaves as expected
}
headers: {
  "Content-Type": "application/json" # results in a scrubbed body as the key is a symbol
}

this is not very user-friendly and will probably result in some people not understanding why the body of their messages are getting scrubbed even when their requests sent has the correct headers