segment/lan_ip: Fix for systems with multiple ips.
segment/lan_ip: Fix for systems with multiple ips.

- Old version returned a list of 3 IPs, breaking the layout
- New version grabs the last IP, which appears to be the correct one
  that we want displayed, at least on this system.
- Also properly quoted variables and process substitution.

blue119/tmux-powerline,JamesKid/tmux-powerline,xinbenlv/tmux-powerline,trkw/tmux-powerline,chocolatemelt/tmux-powerline,naorunaoru/tmux-powerline,yukimemi/tmux-powerline,trkw/tmux-powerline,naorunaoru/tmux-powerline,trkw/tmux-powerline,erikw/tmux-powerline,blue119/tmux-powerline,devmario/tmux-powerline,yukimemi/tmux-powerline,erikw/tmux-powerline,chocolatemelt/tmux-powerline,YOwatari/tmux-powerline,devmario/tmux-powerline,erikw/tmux-powerline,yukimemi/tmux-powerline,xinbenlv/tmux-powerline,devmario/tmux-powerline,chocolatemelt/tmux-powerline,JamesKid/tmux-powerline,naorunaoru/tmux-powerline,YOwatari/tmux-powerline,YOwatari/tmux-powerline,JamesKid/tmux-powerline,xinbenlv/tmux-powerline,blue119/tmux-powerline