Only url encode when using form-urlencoded content type

When using ASP.NET WebAPI with  "Content-Type": "application/json", the
form-urlencoding invalidates the JSON.

//Example
rpc.request({
url: HLeasyXDM.WebAPIFullUrl + uri,
method: reqType,
data: JSON.stringify(data),
headers: {
"blaKey": blaKey,
"blaToken": blaToken,
"Accept": "application/json",
"Content-Type": "application/json"
}
};