Vdirsyncer outputs invalid VCARD files: LF instead of CRLF line endings.

[Tom Sydney Kerckhove]

Before you submit bug reports: https://vdirsyncer.pimutils.org/en/stable/contributing.html

Things to include in your bugreport:

• Your vdirsyncer version: 0.19.2
• Your operating system: Nixos

VCARD files look like this:

file .contacts/default/5afb1f7c8a81195c.vcf 
.contacts/default/5afb1f7c8a81195c.vcf: vCard visiting card, version 3.0, 2nd line does not start with VERSION:, lines not separated by CRLF

"Lines not separated by CRLF" is invalid according to both RFC 2425 and RFC 6350.