Administrators without JIRA access cannot access portal

Summary

Users who are members of administration groups and don't have Jira application access, won't have permission to projects on Customer Portal.

Steps to Reproduce

1. Add user to a Jira admin group (administrators, site-admins or any other group with admin permissions)
2. Make sure that the user doesn't have a Jira application access (JSM/JSW/JWM)
3. As the user, send an email to JSM, or try logging into the portal

Expected Results

• User will be able to view the project on the portal.
• The user's message will be processed.

Actual Results

• You do not have permission to view this Portal.
• The following error will show up in the processing logs: Sign up not available. 

Notes

• Adding the affected user as a Reporter or Request Participant of a JSM request will result in the error: Cannot add user <user> because they are not a customer on this service project

Workaround

• Remove user with no product access from jira-administration groups.
• Admin to get product license as it wont be supported for admin to have application access without proper licensing