Update wikipedia importance sources

[lonvia]

Nominatim has switched the wikipedia importance files to a more light-weight CSV format. The new file is available at https://nominatim.org/data/wikimedia-importance.csv.gz and should go into the place as the former .sql.gz file. Nominatim will automatically pick up the new file.

And while you are at it, you might also want to install the file for secondary importance wikimedia-secondary-importance.sql.gz (needs to be installed as secondary_importance.sql.gz).

Full instructions as usual in the Nominatim docs.