[Fix] Change method for creating filepath to check map data age

[hdevine825]

This PR…

• Resolves an issue where a recent map data file would be downloaded again if the country name includes a slash.

Considerations and implementations

Used the existing function build_osm_pbf_filepath to create the file path to check against instead of the existing method that resulted in checking in a subfolder when a slash was included.

How to test

1. Run with a -co value that includes a slash like us/delaware
2. After download rerun with the same value and the file won't be downloaded again

Pull Request Checklist

• Reviewed the Contributing Guidelines
  • Especially the Pull-Requests section
• Commits (and commit-messages) are understandable
• Tested with macOS / Linux
• Tested with Windows