Hostname is not changed after rebooting

Hi,

I'm trying to change the hostname permanently in my VPS Essential following these instructions:

1) I edited `/etc/cloud/cloud.cfg` and added:
preserve_hostname: true
manage_etc_hosts: false
2) I edited `/etc/hostname` with "mydomain"
3) I edited `/etc/hosts` and have the following:
127.0.0.1 localhost

::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts

127.0.1.1 mydomain.com mydomain

Then when I reboot the VPS I check again the `/etc/hosts` file and had the following:

127.0.0.1 localhost

# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts


127.0.1.1 mydomain.com mydomain
127.0.1.1 vps-XXXXXXXX.vps.ovh.net.novalocal vps-XXXXXXXX

Why is always appending the `127.0.1.1 vps-XXXXXXXX.vps.ovh.net.novalocal vps-XXXXXXXX` line in every reboot if I changed the `/etc/cloud/cloud.cfg` correctly?