Fix OpenIDConnect (replace deprecated logout by getLogoutRedirectUrl)

[stweil]

No description provided.

[stweil]

Commit 0aa344b fixed logout in all auth handlers which used it, but for OpenIDConnect the logout function was added later in ddb53bc. It was working for release 10, but not for releases 11 and 12.

[stweil]

Without this fix, I get the runtime exception "Deprecated methods "logout" and "resetState" needto be replaced by "getLogoutRedirectUrl" and "clearLoginState". Note the missing blank which is fixed in a 2nd commit which I just added.

[stweil]

I still wonder why I got the runtime exception on our test instance after upgrading from release 10 to release 11, while my 2nd test instance which is based on dev-12.0 does not throw this exception although it has the same bug.

The exception also occurs with dev-12.0 when the authentication method is set to "OpenIDConnect".

[demiankatz]

Thanks, @stweil -- this must be a case of two interrelated pull requests getting merged close together without the conflict being noticed. Good catch! I'll merge this today so we can include it in the 11.0.1 bug fix release on Monday.