add res.statusCode for prep

Author: bourgeoa

lib/handlers/get.js

@@ -129,14 +129,16 @@ async function handler (req, res, next) {
       statusCode = 206
     }
 
+    // prep use res status
+    res.statusCode = statusCode
     if (prep && isRdf(contentType) && !res.sendEvents({
       config: { prep: prepConfig },
       body: stream,
       isBodyStream: true,
       headers
     })) return
 
-    res.writeHead(statusCode, headers)
+    res.writeHead(statusCode, headers) // res.set sneds 'charset'
     return stream.pipe(res)
   }