Fix namibia geofk

[davide-f]

Closes # (if applicable).

Changes proposed in this Pull Request

• Fixes "NA" not found in earth-osm
• Drops warning of future unsupported "H" option in favour of "h" for opts
• Drop country tag for lines that sometimes lead to errors in the clustering phase

Checklist

• I consent to the release of this PR's code under the AGPLv3 license and non-code contributions under CC0-1.0 and CC-BY-4.0.
• I tested my contribution locally and it seems to work fine.
• Code and workflow changes are sufficiently documented.
• Newly introduced dependencies are added to envs/environment.yaml and doc/requirements.txt.
• Changes in configuration options are added in all of config.default.yaml and config.tutorial.yaml.
• Add a test config or line additions to test/ (note tests are changing the config.tutorial.yaml)
• Changes in configuration options are also documented in doc/configtables/*.csv and line references are adjusted in doc/configuration.rst and doc/tutorial.rst.
• A note for the release notes doc/release_notes.rst is amended in the format of previous release notes, including reference to the requested PR.

[davide-f]

@arizeosalac this PR should have fixed the issue about assertion error during clustering where country codes mismatched :)