replace lookup_node_ip with get_ip_from_hostname from pve-common
besides some irrelevant implementation details 'lookup_node_ip' is
identical to pve-common's get_ip_from_hostname, as they both rely on
'PVE::Tools::getaddrinfo_all' to get the addresses. So just reuse
the one from common instead of shipping a copy here.
The pve-common's one was recently improved by checking not only the
first IP it gets from getaddrinfo_all, but all and only complain if
none of those is a "real WAN (non-local)" IP. This will help
container installations of PMG with DHCP as their network
configuration option, as those often also have a hosts entry from
hostname to loopback addresses. Also, static setups often have both,
WAN and loopback addresses in /etc/hosts - as getaddrinfo_all gives
use them all do not just check the first.
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>