[5.2] EmailRule unique should look at submitted input data instead of stored form data.

[Flowman]

Pull Request for Issue #43821.

Summary of Changes

Fix that validation is looking for submitted input data instead of stored form data.

Testing Instructions

Code review

or

follow instructions #43821

[degobbis]

I have tested this item ✅ successfully on 16b59a2

Makes sense

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[HLeithner]

This pull request has been automatically rebased to 5.2-dev.

[viocassel]

I have tested this item ✅ successfully on 16b59a2

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[Quy]

RTC

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[Hackwar]

Thank you for your contribution!