fixed issue 43 Warning when saving/deleting zone (undefined index)
fixed issue 43 Warning when saving/deleting zone (undefined index)

mklooss/powerdns-webinterface,ducbo/powerdns-webinterface,catding/powerdns-webinterface,catding/powerdns-webinterface,Spacefish/powerdns-webinterface,Spacefish/powerdns-webinterface,mklooss/powerdns-webinterface,SteveClement/powerdns-webinterface,SteveClement/powerdns-webinterface,ducbo/powerdns-webinterface