Parse options in the RTSP URL only from the last question mark onwards

This helps if the URL (erroneously?) contains question marks within the path.

Originally committed as revision 22643 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/rtsp.c

@@ -1449,7 +1449,7 @@ redirect:
         port = RTSP_DEFAULT_PORT;
 
     /* search for options */
-    option_list = strchr(path, '?');
+    option_list = strrchr(path, '?');
     if (option_list) {
         /* Strip out the RTSP specific options, write out the rest of
          * the options back into the same string. */