This change fixes an issue where a formerly warned/frozen user will be
warned again even though they have made payment for the invoice that got
them frozen in the first place. A payment status check is now made
right before a warn/freeze event to make sure the invoice hasn't been
paid already.
Issue: https://github.com/storj/storj/issues/5931
Change-Id: I3f6ac1e224f40107d58dc8f7bdbce58bbbea0196
Fix an error that can occur when processing multiple invoices for the same user in a single invoice cycle when the user is paying with Storj tokens.
Change-Id: I54af8c7dde1965d994f687fdfc4e4b5ef4deeb2d
