FN cardinality is 1*, allows multiple properties

[bartbutler]

Hello, great library! One minor issue is that the vCard validation generates a warning entry if the there is more than 1 FN property in the vCard. According to everything I've been able to find, multiple FN properties should be allowed.

https://tools.ietf.org/html/rfc6350#section-6.2.1

[evert]

looks like you're right. This is a bug