Security Threat Tool: User with viewer role sees 'STT disabled' instead of 'Insufficient access' (even when STT enabled)

User impact:
Insufficient access rights message is not displayed for a user with a viewer role at Database checks page. It always says 'STT disabled'. Even if it is enabled.

Steps to reproduce:

1. disable STT as an admin
2. create a user with the viewer role
3. login as a viewer
4. open Database Checks page

Actual result:
Security Threat Tool is disabled. You can enable it in PMM Settings message

Expected result:

Insufficient access rights. message should be displayed when STT enabled or disabled