System Admin must be member of application to see customer portal

Environment

• JIRA Service Desk 3.0+

Steps to Reproduce

1. Create a customer Portal
2. Add a user to be the System Administrator
3. Add this user as a member to jira-servicedesk-users
4. Browse to the customer portal
5. Remove the Sys Admin from the jira-servicedesk-users and try to browse to the customer portal
6. The sysadmin will see "You don't have permission to access any Customer Portal"

Expected Results

The System Administrator should be able to access the customer portal as a regular customer.

Actual Results

It throws the access error.

Workaround

JIRA Admins can be added to jira-core-users or jira-software-users, so that the Service Desk license will be saved as intended.