use the modern name for this option

docs/examples/curlx.c

@@ -453,7 +453,7 @@ int main(int argc, char **argv) {
   {
     FILE *outfp;
     BIO_get_fp(out,&outfp);
-    curl_easy_setopt(p.curl, CURLOPT_FILE,outfp);
+    curl_easy_setopt(p.curl, CURLOPT_WRITEDATA, outfp);
   }
 
   res = curl_easy_setopt(p.curl, CURLOPT_SSL_CTX_FUNCTION, sslctxfun)  ;