Fix ifconfig parsing

ifconfig does not output "inet.*addr:" pattern anymore. Match IP addresses instead.

$ /sbin/ifconfig wlp2s0 | grep 'inet.*addr:'

$ /sbin/ifconfig wlp2s0 | grep 'inet [0-9][0-9]*.[0-9][0-9]*.[0-9][0-9]*.[0-9][0-9]*'

  inet 192.168.1.5  netmask 255.255.255.0  broadcast 192.168.1.255

Closes: #892772