Fix voor tracker 29719 (Some errors occurred while populating the database)

This is a fix for tracker http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=29719

The current joomla.sql can generate the error:
Some errors occurred while populating the database: SQL=INSERT INTO `*_usergroups` (`id`, `parent_id`, `lft`, `rgt`, `title`) VALUES (1, 0, 1, 18, 'Public'), (2, 1, 8, 15, 'Registered'), (3, 2, 9, 14, 'Author'), (4, 3, 10, 13, 'Editor'), (5, 4, 11, 12, 'Publisher'), (6, 1, 4, 7, 'Manager'), (7, 6, 5, 6, 'Administrator'), (8, 1, 16, 17, 'Super Users'), (9, 1, 2, 3, 'Guest')