Error when updating display name and avatar URL

Created by: justdueck

• Sourcegraph version:
• Platform information:

Steps to reproduce:

1. Update Display Name and Avatar URL in user settings
2. Hit 'Save'

Expected behavior:

Saves successfully and updates display name and avatar

Actual behavior:

Receives Error: unable to change username because auth.enableUsernameChanges is false in site configuration

Customer support ticket: https://sourcegraph.atlassian.net/jira/servicedesk/projects/SG/queues/custom/2/SG-420