text/x-card is deprecated in favour of text/card

Quoting the [RFC6350, Section 10.1. Media Type Registration](https://tools.ietf.org/html/rfc6350#section-10.1):
>       In addition, the following media types are known to have been used
>       to refer to vCard data.  They should be considered deprecated in
>       favor of text/vcard.
>
>       *  text/directory
>       *  text/directory; profile=vcard
>       *  text/x-vcard