smart-http: Really never use Expect: 100-continue

libcurl may choose to try and use Expect: 100-continue for
any type of POST, not just a Transfer: chunked-encoding type.
Force it to disable this feature, as not all proxy servers support
100-continue and leaving it enabled can cause 1 second stalls during
the negotiation phase of fetch-pack/upload-pack.

In ("206b099d26 smart-http: Don't use Expect: 100-Continue") we
tried to disable this for only large POST bodies, but it should be
disabled for every POST body.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

remote-curl.c

@@ -453,12 +453,12 @@ static int post_rpc(struct rpc_state *rpc)
 
 	headers = curl_slist_append(headers, rpc->hdr_content_type);
 	headers = curl_slist_append(headers, rpc->hdr_accept);
+	headers = curl_slist_append(headers, "Expect:");
 
 	if (large_request) {
 		/* The request body is large and the size cannot be predicted.
 		 * We must use chunked encoding to send it.
 		 */
-		headers = curl_slist_append(headers, "Expect:");
 		headers = curl_slist_append(headers, "Transfer-Encoding: chunked");
 		rpc->initial_buffer = 1;
 		curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, rpc_out);