postinstall check fontconfig

[Roy Marples]

Hi List

For quite some time now, postinstall keeps on failing fontconfig check
because I don't have X11 installed on this headless box.
This patch now passes populate_dir if the target directory does not
exist which solves me problem. I don't know if what the intent of the
function is if the directory does not exist or not, hence me asking the
peanut gallery here.

Thanks

Roy