Activate root output if RandR request fails.
Activate root output if RandR request fails.

fixes #2011

stapelberg/i3,stapelberg/i3,Airblader/i3-original,i3/i3,Airblader/i3-original,stapelberg/i3,Airblader/i3-original,Airblader/i3,i3/i3,Airblader/i3,Airblader/i3,Airblader/i3-original,stapelberg/i3,i3/i3,i3/i3,Airblader/i3,Airblader/i3-original