Updated SDL stable version prompt (#34)

Author: Cyrodwd

include/header.inc.php

@@ -1,5 +1,5 @@
 <div id="header">                
     <div id="download_hint" class="box">
-        Get the current <strong>stable</strong> <a href="https://github.com/libsdl-org/SDL/releases/latest">SDL version 3.2.6</a><br />
+        Get the current <strong>stable</strong> <a href="https://github.com/libsdl-org/SDL/releases/latest">SDL version 3.2.8</a><br />
     </div>
 </div>