Fix #7834: Delete IPFW pipes when disable Captive Portal zone
Fix #7834: Delete IPFW pipes when disable Captive Portal zone

pfsense/pfsense,dennypage/pfsense,pfsense/pfsense,pfsense/pfsense,dennypage/pfsense,pfsense/pfsense,ptorsten/pfsense,NewEraCracker/pfsense,dennypage/pfsense,ptorsten/pfsense,ptorsten/pfsense,phil-davis/pfsense,dennypage/pfsense,phil-davis/pfsense,phil-davis/pfsense,phil-davis/pfsense,NOYB/pfsense,NewEraCracker/pfsense,NewEraCracker/pfsense,NOYB/pfsense,NewEraCracker/pfsense,NOYB/pfsense