Adding oidc email scope check

[nabokihms]

This helps to avoid "no email claim" error if the email scope was not specified.

Signed-off-by: m.nabokikh maksim.nabokikh@flant.com

Closes #1598

[sagikazarmark]

LGTM, only a few suggestions

[sagikazarmark]

This check is not necessary because of default values.

[sagikazarmark]

I would revert this, because it doesn't change behavior at all.

[sagikazarmark]

Further thinking about this: email claim will only be included in the returned token if email scope is requested. Given this wasn't the behavior before, one could interpret this as a breaking change. I'm not sure what the standard says about returning non-requested fields, but if nothing, then we should probably continue returning those fields in case the underlying provider returns them.

[nabokihms]

Yep, it has sense. I will change the behavior according to your thoughts.

[sagikazarmark]

A few more nits

[sagikazarmark]

How about:

	hasEmailScope := false

	for _, s := range c.oauth2Config.Scopes {
		if s == "email" {
			hasEmailScope = true

			break
		}
	}

Feels a bit cleaner and more readable

[sagikazarmark]

You could merge these two ifs. The default value of email is an empty string because of the type.

[nabokihms]

Yep, you are right. Fixed.

[sagikazarmark]

Thanks @nabokihms

[bonifaido]

LGTM!