We've recently been unable to backup from gitea09 to the vexxhost backup
server. Testing indicates that ipv6 connectivity between the two servers
is the likely issue. Address this by forcing all backups to run over
ipv4 instead of ipv6. We could restrict this to only gitea09 if we
wanted to and/or only when the vexxhost server is the target, but this
is the simplest way to make the change in the existing configuration
management.
Change-Id: Ic868ded7d923b822d757a57416f879fd59c003e9
4d25261bb6