fix debug log message when userid is None

[eyetheekh]

summary

The log message formats the string using % userid, but the string does not contain a formatting placeholder, which causes:

TypeError: not all arguments converted during string formatting

This removes the % userid from the log message since its None anyway.

to reproduce

from pyramid.authentication import RepozeWho1AuthenticationPolicy class DummyRequest: environ = {"repoze.who.identity": {"repoze.who.userid": None}} def _log(msg, methodname, request): print(msg) policy = RepozeWho1AuthenticationPolicy() policy.debug = True policy._log = _log request = DummyRequest() result = policy.authenticated_userid(request) # raises type error