log when feed is already being received

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@13939 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

ffserver.c

@@ -1341,6 +1341,7 @@ static int http_parse_request(HTTPContext *c)
     /* If already streaming this feed, do not let start another feeder. */
     if (stream->feed_opened) {
         snprintf(msg, sizeof(msg), "This feed is already being received.");
+        http_log("feed %s already being received\n", stream->feed_filename);
         goto send_error;
     }