Charon.ftp can't handle IPv6

[KarlaZinreich]

I'm running a fairly standard debian 7.8 as a hetzner root server.
While the backup script runs normally, charon.ftp wasn't able to access the FTP server.

I got the error:

Unable to connect to server at /usr/sbin/charon.ftp line 153

After some investigation I found out, that the backup ftp server has a IPv6 adress.
Unfortunately, my current version of NET::FTP wasn't able to handle IPv6 adresses.
I had to replace

    require Net::FTP;

with

    require Net::INET6Glue::FTP;
    require Net::FTP;

on line 132, in order to make it work.

I know this is not a charon specific error, but maybe you can provide a fallback for this case?