When enforcing a specific OpenID provider, for example

$wgOpenIDForcedProvider = "http://www.opensuse.org/openid/user/";

I'd like to be able to skip the "finish" step with its options to select a wiki username to assign to the logged in OpenID account. Instead, the username should be taken from the OpenID account, so if you login as user "cboltz" on www.opensuse.org, the wiki should enforce "cboltz" as username.

Of course something like this doesn't make sense when allowing multiple OpenID providers, so it should be a config option (disabled by default).

(See http://lists.opensuse.org/heroes/2017-02/msg00000.html for more details.)