Code style: replace "array()" with "[]"

This was an automatic mass-replace. Manual replacement of array(...)
will continue

design/privateheader.php

@@ -117,7 +117,7 @@ $NotificationsManager = new NotificationsManager(G::$LoggedUser['ID']);
 $Notifications = $NotificationsManager->get_notifications();
 $UseNoty = $NotificationsManager->use_noty();
 $NewSubscriptions = false;
-$NotificationSpans = array();
+$NotificationSpans = [];
 foreach ($Notifications as $Type => $Notification) {
   if ($Type === NotificationsManager::SUBSCRIPTIONS) {
     $NewSubscriptions = true;
@@ -339,8 +339,8 @@ if (check_perms('site_send_unlimited_invites')) {
     </div>
 <?
 //Start handling alert bars
-$Alerts = array();
-$ModBar = array();
+$Alerts = [];
+$ModBar = [];
 
 // Staff blog
 if (check_perms('users_mod')) {