Hide countdown as soon as race ends

[supertuxkart-sourceforge-migration]

Author: auria

As reported on http://forum.freegamedev.net/viewtopic.php?p=52853#p52853

The countdown in the race GUI remains visible for a very short time after crossing the finish line, before the results are shown. The timer will then show a time lower than your actual time, and it may even say "challenged failed" even though you actually won. The solution would be to either hide or freeze the countdown immediately on crossing the finish line

Migrated-From: https://sourceforge.net/apps/trac/supertuxkart/ticket/1118

[supertuxkart-sourceforge-migration]

Author: sachith500 I sent a pull request.

https://github.com/supertuxkart/stk-code/pull/41