cups/dest.c: Write data into /etc/cups/lpoptions if we're root
cups/dest.c: Write data into /etc/cups/lpoptions if we're root

Fixes #454 , the patch is created by Yair Yarom
(https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1008053).

OpenPrinting/cups,OpenPrinting/cups,OpenPrinting/cups,OpenPrinting/cups