Referral link doesn't handle deleted user

Summary

When a referal user has been banned they still appear in the referring link column

Steps to reproduce

1. Create a new channel using a referral link.
2. Get the channel banned by writing a blog withing 20 minutes of creation.
3. Log into the referring account
4. Go to https://www.minds.com/wallet/tokens/referrals
5. Open console

What is the current bug behavior?

Cannot read username of null

What is the expected correct behavior?

Code should handle banned users

Relevant logs and/or screenshots