Account Withholding Tax Rate; now treated as "declared" if declared and undeclared rates are the same

When displaying information about Account Withholding Tax Rates an Account may no longer be treated as using the "undeclared" Rate if the declared and undeclared rates are the same.

For example, in New Zealand Non Residents would not normally have an IRD Number, but then the Tax Category should be defined having the same declared and undeclared rates. Hence warnings that the Account is using an undeclared rate no longer show.