libcurl-tutorial: fix two typos.

Setting the last \fIcurl_mime_headers\fP argument to TRUE would have caused

the headers to be automatically released upon destroyed the multi-part, thus

saving a clean-up call to \fPcurl_slist_free_all(3)\fP.

saving a clean-up call to \fIcurl_slist_free_all(3)\fP.

.nf

 curl_formadd(&post, &last,

corresponding part header.

Upon sending such a message, libcurl prepends it with the header list

set with \fICURLOPT_HTTPHEADERS(3)\fP, as 0th-level mime part headers.

set with \fICURLOPT_HTTPHEADER(3)\fP, as 0th-level mime part headers.

Here is an example building an e-mail message with an inline plain/html text

alternative and a file attachment encoded in base64:

 headers = curl_slist_append(headers, "To: you@example.com");

 /* Set these into the easy handle. */

 curl_easy_setopt(easyhandle, CURLOPT_HTTPHEADERS, headers);

 curl_easy_setopt(easyhandle, CURLOPT_HTTPHEADER, headers);

 curl_easy_setopt(easyhandle, CURLOPT_MIMEPOST, mime);

.fi