RFR: 1725: Clarify "no known role" error message [v2]

[Zhao Song]

On Fri, 10 Feb 2023 14:04:41 GMT, Erik Joelsson <erikj at openjdk.org> wrote:

> Until we have a better field for this stored somewhere in the census data, I would prefer the domain field raw without modification.

It will be `no known openjdk.org user` and `no known oracle.com user`.  I think it's also ok.

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PR: https://git.openjdk.org/skara/pull/1459