Try to avoid redacting international phone numbers that look like valid credit card numbers

If a number passes Luhn check and has a major credit card prefix, but starts with `+`, it's probably an international phone number, so don't redact it.

For example, some UK phone numbers start with `+44` (Isle of Man) which could look like a Visa card, since all we know about Visa for sure is that it starts with `4`.

@vkmita