Revert "Fix for order edit when currency is different"

This reverts commit 2c33d41bd69d49fca8f8ddc1829381112d2901f8.
Fix for order edit when currency is different
Fixes for vat_validation function

Add missing country Croatia.

Check prefixes match as French VAT numbers
can start with 2 letters. Also prevents numbers for other countries
passing.
Prevent shipping address entry in PayPal standard
Fixed 404 headers

https://github.com/opencart/opencart/issues/1620