Fixes [#662] - double slash in install.xml path.

htdocs/lib/upgrade.php

@@ -198,7 +198,7 @@ function check_upgrades($name=null) {
 function upgrade_core($upgrade) {
     global $db;
 
-    $location = get_config('libroot') . '/db/';
+    $location = get_config('libroot') . 'db/';
 
     db_begin();