3.1-dev Database Updater keeps running group_legend query

The updater keeps running this query:

UPDATE phpbb_groups SET group_legend = 1 WHERE group_id = 5

On repeated runs of database update for 3.1-dev, the updater should recognize it already performed updates and skip this. So that if you manually set group_legend = 0 for that group, it is not reset by the updater every time you run it.