fix missing css

[psorensen]

Description of the Change

Fixes a missing script. The admin-settings.css and admin.css had identical IDs when be enqueued, causing the admin-settings.css not to load, thus breaking the Registration Key validity indicator.

Closes #1207

How to test the Change

1. Visit Distributor -> Settings
2. Enter a valid or invalid registration key and click save settings
3. Observe the indicator icon next to the input displays

Changelog Entry

Fixed - Missing admin script

Credits

Props @psorensen

Checklist:

• [x] I agree to follow this project's Code of Conduct.
• [x] I have updated the documentation accordingly.
• [ ] I have added tests to cover my change.
• [ ] All new and existing tests pass.