network: systemd-networkd-wait-online fix arg -i

systemd-networkd-wait-online does not accept '-i'
command line argument. This patch fixses it .

$ /usr/lib/systemd/systemd-networkd-wait-online --help
systemd-networkd-wait-online [OPTIONS...]

Block until network is configured.

  -h --help                 Show this help
     --version              Print version string
  -q --quiet                Do not show status information
  -i --interface=INTERFACE  Block until at least these interfaces have appeared
$ /usr/lib/systemd/systemd-networkd-wait-online -i br0
/usr/lib/systemd/systemd-networkd-wait-online: invalid option -- 'i'
$ /usr/lib/systemd/systemd-networkd-wait-online --interface=br0