RPZ: bug fix and code update

RPZ: bug fix and code update

changed all paths from `/var/ipfire/rpz/` to `/var/ipfire/dns/rpz/`
(thank you to Adolf!)

rpz-config:
 - bug: corrected "Type" test from block to allow
 - removed verbose parameter from various commands

rpz-metrics:
 - bug: corrected grep for rpz name count
 - bug: fixed divide by zero error (thank you Peppe!)

install/uninstall:
 - bug: corrected scripts (thank you Bernhard!)

Signed-off-by: Jon Murphy <jon.murphy@ipfire.org>