Merge branch 'restrict-default-addressbook-privileges' into 'master'

Set default privileges to none to prevent other users from accessing address books

See merge request davical-project/davical!146

inc/schedule-functions.php

@@ -312,7 +312,7 @@ function processItipCancel( vCalendar $vcal, vProperty $attendee, WritableCollec
 
   if ( $attendee_calendar->actualDeleteCalendarMember($row->dav_name) === false ) {
     dbg_error_log('ERROR', 'Could not delete calendar member %s for %s',
-                                    $row->dav_name, $attendee->Value());
+                                    $row->dav_name(), $attendee->Value());
     trace_bug('Failed to write scheduling resource.');
     return '5.2';
   }