tiny indent fix

lib/transfer.c

@@ -752,7 +752,7 @@ static CURLcode header_append(struct SessionHandle *data,
                               struct SingleRequest *k,
                               size_t length)
 {
-    if(k->hbuflen + length >= data->state.headersize) {
+  if(k->hbuflen + length >= data->state.headersize) {
     /* We enlarge the header buffer as it is too small */
     char *newbuff;
     size_t hbufp_index;