Use correct info to decide when to show VAT fields

Use correct info to decide when to show VAT fields

The VAT refund fields on anything should be driven off whether there's
actual VAT on the invoice, not off the EU_VAT setting. In particular,
when using taxes and not being in the EU, EU_VAT should be turned off,
but we must still be able to refund the VAT...

Diagnosed by Steve Singer