Stop using discontinued Google+ userinfo endpoint

[davido]

Starting from 7. March, Google is going to discontinue its Google+ userinfo endpoint: [1].

The Google+ Sign-in feature is fully deprecated and is being shut down on March 7, 2019.
This will be a progressive shutdown, with intermittent failures starting as early as January 28, 2019.
Developers should migrate to the more comprehensive Google Sign-in authentication system.
Please see our migration tips.

So that the currently used Google+ userinfo endpoint: https://www.googleapis.com/userinfo/v2/me should be replaced with: https://www.googleapis.com/oauth2/v2/userinfo. See a similar discussion in context of this issue: [2].

• [1] https://developers.google.com/+/web/signin/
• [2] Google+ shutdown will break OAuth provider dotnet/aspnetcore#6069

[davido]

Should be fixed with: [1].

• [1] https://gerrit-review.googlesource.com/c/plugins/oauth/+/212441

[davido]

Just noticed, that the documentation: [1] references this endpoint with version 3:

  https://www.googleapis.com/oauth2/v3/userinfo

[1] https://developers.google.com/identity/protocols/OpenIDConnect

[davido]

Released in: [1].

[1] https://github.com/davido/gerrit-oauth-provider/releases/tag/v3.0.0