[statistics] bug fix - projectID issue (aces#9170)

Fixes error on statistics page:

```
[CRITICAL] /var/www/Loris/php/libraries/User.class.inc:476: Uncaught TypeError: User::hasProject(): Argument #1 ($projectID) must be of type ProjectID, string given, called in /var/www/Loris/modules/statistics/php/statistics_site.class.inc on line 134 and defined in /var/www/Loris/php/libraries/User.class.inc:476
```

Fixes aces#9137

modules/statistics/php/statistics_site.class.inc

@@ -98,9 +98,9 @@ class Statistics_Site extends \NDB_Menu
     {
 
         //SITES
-
-        $factory = \NDB_Factory::singleton();
-        $user    = $factory->user();
+        $projectID = new \ProjectID(strval($projectID));
+        $factory   = \NDB_Factory::singleton();
+        $user      = $factory->user();
 
         if (!empty($centerID) && $user->hasCenter($centerID)) {
             $this->query_criteria   .= " AND s.CenterID =:cid ";