Cygwin: pty: Not to change code page of parent console.

- The recent commit "Cygwin: pty: Fix timing of creating invisible
  console." breaks the feature added by commit 72770148, which
  prevents pty from changing code page of parent console. This patch
  restores that.

winsup/cygwin/fhandler_console.cc

@@ -1610,7 +1610,7 @@ fhandler_console::close ()
   if (con_ra.rabuf)
     free (con_ra.rabuf);
 
-  if (!have_execed)
+  if (!have_execed && !invisible_console)
     free_console ();
   return 0;
 }