Entire 'last_triggered' column update when a schedule is triggered

[carlos-bailon]

I have found that, when any fixed schedule is triggered, the whole 'last_updated' column of the database is updated with its value, not only the row of this schedule. It causes an issue with random schedules, as their 'last_triggered' value must be 0 to be recognised as random. In the end, when a fixed schedule is triggered, subsequent random schedules are never triggered.