dashes instead of underscores in language codes

[Andre Engels]

When there is a dash in the language code (for example, bat-smg.wikipedia.org), the game uses an underscore instead. Because of this, for these languages, the page does not load.

[TMg_]

An example is https://www.wikidata.org/wiki/Q13191868 which links to https://bat_smg.wikipedia.org/wiki/Dorin_Sandulescu in the game but should link to https://bat-smg.wikipedia.org/wiki/Dorin_Sandulescu

[Lokal Profil]

This is due to how wikidata stores sitelinks. E.g. for the example above wikidata stores bat-smg.wikipedia.org as bat_smgwiki.

This is similar to the Norwegian (Bokmal) issue in #63

I'll fix a pull request to fix this.

[Magnus Manske]

Fixed by @lokal-profil