Fix ifconfig parsing

Fix ifconfig parsing

ifconfig from net-tools does not output "inet.*addr:" pattern anymore.
Match IP addresses instead. But ifconfig from busybox does, so try
and match either patterns.

$ /sbin/ifconfig wlp2s0 | grep 'inet.*addr:'
$ /sbin/ifconfig eth0 | grep -E 'inet.*addr:|inet [0-9][0-9]*.[0-9][0-9]*.[0-9][0-9]*.[0-9][0-9]*'
        inet 192.168.1.91  netmask 255.255.255.0  broadcast 192.168.1.255
$ busybox ifconfig eth0 | grep -E 'inet.*addr:|inet [0-9][0-9]*.[0-9][0-9]*.[0-9][0-9]*.[0-9][0-9]*'
          inet addr:192.168.1.91  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fd00::1:60ad:2691:4cc6:f32/64 Scope:Global
          inet6 addr: fe80::96de:80ff:feae:b976/64 Scope:Link
          inet6 addr: fd00::1:96de:80ff:feae:b976/64 Scope:Global
          inet6 addr: 2a00:23c5:be85:1400:96de:80ff:feae:b976/64 Scope:Global
          inet6 addr: 2a00:23c5:be85:1400:60ad:2691:4cc6:f32/64 Scope:Global

Closes: #892772