Remove Advisors from showing up in Waiver Logs

[sonikavuyyuru]

In the waiver automated checkoff process, any waiver that has a username/email that does match an existing user shows up in Waiver Logs and needs to be manually checked off. Advisors' waivers do not need to be checked off, so they do not need to appear here in the waiver logs, but at current, they do.

If the username field of the waiver checks out to be an advisor's username, it can be ignored and need not be logged in Waiver Logs.