crashes If any of the 3 monitors is disabled via xrandr

[dudman]

I have 3 monitors when they are all enabled works fine, however if I disable any with
xrandr --output DVI-I-0 --mode 1920x1080 --pos 3840x0 --rotate normal --output DVI-I-1 --off --output HDMI-0 --off --ou tput DP-0 --primary --mode 1920x1080 --pos 1920x0 --rotate normal --output DP-1 --off --output DVI-D-0 --off

Then I get the following...
`panic: runtime error: index out of range [1] with length 1

goroutine 1 [running]:
main.fetchDisplays(0x4058bf, 0xc000016118, 0x0, 0x0, 0x0)
/home/user/git/autoplank/main.go:177 +0x62b
main.main()
/home/user/git/autoplank/main.go:22 +0x26
`