3.19 - Font url not detected in some template

[jeawhanlee]

Describe the bug
While using this template, we can observe that we get File not found in the array.

To Reproduce
Steps to reproduce the behavior:

1. Set WP_ROCKET_DEBUG to true
2. Visit a page that uses this template
3. Open console
4. Check the above the fold fonts data and see array entries with 'File not found'

Expected behavior
There should be no entries having 'File not found' in the final result returned.

Screenshots

Additional context
Add any other context about the problem here.