Using Domain User Default with Domain Access 2.x version

2.x version of DA now stores default domain in the database and is passed as 0 not -1. This requires executing the following update when upgrading from 1.x to 2.x:

function domain_user_default_update_6200() {
$ret = array();
$ret[] = update_sql("UPDATE {domain_user_default} SET domain_id = 0 WHERE domain_id = -1");
return $ret;
}