Update instances of some obsolete CURLOPTs to their new names

docs/libcurl/libcurl-tutorial.3

@@ -1058,7 +1058,7 @@ to 1.
 What might be even more useful, is libcurl's ability to separate the headers
 from the data and thus make the callbacks differ. You can for example set a
 different pointer to pass to the ordinary write callback by setting
-\fICURLOPT_WRITEHEADER(3)\fP.
+\fICURLOPT_HEADERDATA(3)\fP.
 
 Or, you can set an entirely separate function to receive the headers, by using
 \fICURLOPT_HEADERFUNCTION(3)\fP.

docs/libcurl/libcurl.m4

@@ -153,7 +153,7 @@ int x;
 curl_easy_setopt(NULL,CURLOPT_URL,NULL);
 x=CURL_ERROR_SIZE;
 x=CURLOPT_WRITEFUNCTION;
-x=CURLOPT_FILE;
+x=CURLOPT_WRITEDATA;
 x=CURLOPT_ERRORBUFFER;
 x=CURLOPT_STDERR;
 x=CURLOPT_VERBOSE;