collectd.conf: Change chain from HOSTILE to HOSTILE_DROP - fixes bug#12838
- Chain that was specified was HOSTILE but actual used is HOSTILE_DROP
- Using HOSTILE caused no update fro the hostile data used in the Firewall Hits graph
Fixes: bug#12838 Tested-by: Adolf Belka <adolf.belka@ipfire.org> Signed-off-by: Adolf Belka <adolf.belka@ipfire.org> Reviewed-by: Bernhard Bitsch <bbitsch@ipfire.org> Acked-by: Bernhard Bitsch <bbitsch@ipfire.org>