Fix for crash in webserver.c by Sebastian Brandt

Dear libupnp-devels,
when POST'ing to the simple web server in libupnp, the application crashes.
This is caused by a missing "..." argument in webserver.c:1533.
Seems it has been there for a long time ... 1.6.9 and 1.6.18 have it.

webserver.c:1533 calls http_MakeMessage
/* Send response. */
http_MakeMessage(&headers, 1, 1,
	 "RTLSXcCc",
	 ret, "text/html", X_USER_AGENT);
The format parameter RTLSXcCc needs four arguments -
R - response code - ret,
T- content type - text/html,
L - struct SendInstruction * - NOT PRESENT
X - user agent - X_USER_AGENT

This results in a crash.

Changing to
http_MakeMessage(&headers, 1, 1,
	 "RTLSXcCc",
	 ret, "text/html", &RespInstr, X_USER_AGENT);
solves the situation.

Yours,
Sebastian Brandt

upnp/src/genlib/net/http/webserver.c

@@ -1531,7 +1531,7 @@ void web_server_callback(http_parser_t *parser, INOUT http_message_t *req,
 			/* Send response. */
 			http_MakeMessage(&headers, 1, 1,
 				"RTLSXcCc",
-				ret, "text/html", X_USER_AGENT);
+				ret, "text/html", &RespInstr, X_USER_AGENT);
 			http_SendMessage(info, &timeout, "b",
 				headers.buf, headers.length);
 			break;