Bug 1510082: fatal error missing function format_notification_whitespace()

Just need to require once 'activity.php'

behatnotneeded

Change-Id: Ie1de5b2b50f3de1c367bfa33f8bf4c412c40b0c8
Signed-off-by: Robert Lyon <robertl@catalyst.net.nz>

htdocs/blocktype/inbox/lib.php

@@ -43,6 +43,7 @@ class PluginBlocktypeInbox extends SystemBlocktype {
     public static function render_instance(BlockInstance $instance, $editing=false) {
         global $USER, $THEME;
         $configdata = $instance->get('configdata');
+        require_once('activity.php');
 
         $desiredtypes = array();
         foreach($configdata as $k => $v) {