proFTPD unable to determine IP address
Please change /etc/hosts
from
88.198.61.237 Debian-70-wheezy-64-minimal
2a01:4f8:131:2a::2 Debian-70-wheezy-64-minimal
to
88.198.61.237 web-amd-3700-2gb
2a01:4f8:131:2a::2 web-amd-3700-2gb
or (better) fix the setup to have a proper FQDN and naming scheme.