Windows titlebar fix

[Gisle Vanem]

ws_percenttitle() should not be called in quiet mode since ws_changetitle() 
AFAICS is only called in verbose mode. That caused an assert in 
mswindows.c. An easy patch:

--- CVS-latest\src\retr.c       Sun Dec 14 14:35:27 2003
+++ src\retr.c  Tue Mar 02 21:18:55 2004
@@ -311,7 +311,7 @@
       if (progress)
        progress_update (progress, ret, wtimer_read (timer));
 #ifdef WINDOWS
-      if (toread > 0)
+      if (toread > 0 && !opt.quiet)
        ws_percenttitle (100.0 *
                         (startpos + sum_read) / (startpos + toread));
 #endif

--gv