Don't skip flag requests for events that were previously skipped and not flagged

[dcadenas]

If the event that the user want to "send to nos" was previously processed by cleanstr, it will be ignored and it won't let you send it to the slack channel. So I think we are safe to skip if the event was processed AND was flagged. But if it was processed but not flagged in the past, it should be accepted for the manual analysis