meson - fix dir_sysconf to be under the prefix as it was not
meson - fix dir_sysconf to be under the prefix as it was not

dir_sysconf was set to "etc". not even a /.  this meant
enlightenment_sys couldnt find/load sysactions.conf as it used a
non-relocatable fixed location due to security (setuid root) reasons.

tasn/enlightenment,tasn/enlightenment,tasn/enlightenment