[Self-Issued ID Token Validation] reference to a not existent Section

[Giuseppe De Marco]

In https://openid.bitbucket.io/connect/openid-connect-self-issued-v2-1_0.html#section-7.4-2.1.1 there is a reference to section 3.1.3 but this section is not present in the document, nor is it was not clear to me to which external document it refers

[Kristina Yasuda]

This has been fixed in the recent editorial PRs