Fix typos in the app-base message for incomplete federated login

Hi Bradley,

Daniela spotted some typos on the "federated-login-incomplete" page just before we released the attribute validator in Tuakiri:
* There was a typo in the word amend (was incorrectly spelled ammend)
* The text was referring to "highlighted missing attributes", but the attributes are not highlighted, they are listed as bullet points - so we changed the text accordingly.