Resolve "Unable to see system header and footer form with Ultimate license"

What does this MR do?

The problem is described in detail here

In sum, there was a typo in the License check that prevented the user from seeing the system and header footer settings in the admin dashboard.

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• EE specific content should be in the top level /ee folder
• For a paid feature, have we considered GitLab.com plans, how it works for groups, and is there a design for promoting it to users who aren't on the correct plan?

What are the relevant issue numbers?

Closes #7255 (closed)