Remove link to the sandbox from configuration tab.

If we want to access the sandbox, we can do that from admin/ or type the URL directly.

modules/core/www/frontpage_config.php

@@ -53,14 +53,6 @@ $links_config[] = array(
 	'text' => '{core:frontpage:link_phpinfo}'
 );
 
-$links_config[] = array(
-	'href' => \SimpleSAML\Utils\HTTP::getBaseURL() . 'admin/sandbox.php',
-	'text' => '{core:frontpage:link_sandbox}'
-);
-
-
-
-
 $allLinks = array(
 	'links'      => &$links,
 	'welcome'    => &$links_welcome,