web gui 'network' has error 'active' value if debian ipv6 is disabled

[languanghao]

For some reason, I disable the debian ipv6, after that in the 'network' tab of web gui the 'vmbr0' property 'Active' become 'No'.

I find the error code in 'INotify.pm':

if ($proc_net_if_inet6) {
    while (defined ($line = <$proc_net_if_inet6>)) {
        if ($line =~ m/^[a-f0-9]{32}\s+[a-f0-9]{2}\s+[a-f0-9]{2}\s+[a-f0-9]{2}\s+[a-f0-9]{2}\s+(\S+)$/) {
        $ifaces->{$1}->{active} = 1 if defined($ifaces->{$1});
        }
    }

If ipv6 was disabled, then commond 'ifconfig' output won't contain the line like 'inet6 addr: fe80::d250:99ff:fe0d:d042/64 Scope:Link'.

The logic for check iface is active may change to a different way.

I use follow command to disable ipv6

echo "1" > /proc/sys/net/ipv6/conf/all/disable_ipv6