code optimization (#1025)

- remove mc from Ubuntu
- change archive mirrors for Ubuntu
- small tweaks

install/devuan-v5-install.sh

@@ -80,6 +80,8 @@ $STD apt-get install -y mc
 msg_ok "Installed Dependencies"
 
 echo "export TERM='xterm-256color'" >>/root/.bashrc
+echo -e "$APPLICATION LXC provided by https://tteck.github.io/Proxmox/\n" > /etc/motd
+chmod -x /etc/update-motd.d/*
 if [[ "${SSH_ROOT}" == "yes" ]]; then sed -i "s/#PermitRootLogin prohibit-password/PermitRootLogin yes/g" /etc/ssh/sshd_config; systemctl restart sshd; fi
 
 msg_info "Cleaning up"