Handle OIDC errors

[Dima Tisnek]

I try http://localhost:3000/openid-connect/redirect_uri?error=access_denied&state=123 (that's my exported port), all I get is an entry in the nginx error log:

==> /var/log/nginx/error.log <==
2020/03/16 09:44:43 [error] 393#393: *17 # _oauth2_openidc_redirect_uri_handler: invalid request to the redirect_uri: code parameter could not be found [error=access_denied&state=123], client: 172.17.0.1, server: , request: "GET /openid-connect/redirect_uri?error=access_denied&state=123 HTTP/1.1", host: "localhost:3000"

I'd imagine some handling for error response. I'm not sure what it ought to be though.

[Hans Zandbelt]

yes, the module is in beta right now, error handling is certainly something that needs to be added/improved