Fix NanoBSD snapshot URL default.
Fix NanoBSD snapshot URL default.

NewEraCracker/pfsense,BlackstarGroup/pfsense,ch1c4um/pfsense,ptorsten/pfsense,NOYB/pfsense,brunostein/pfsense,ptorsten/pfsense,phil-davis/pfsense,ch1c4um/pfsense,pfsense/pfsense,pfsense/pfsense,dennypage/pfsense,dennypage/pfsense,ptorsten/pfsense,NewEraCracker/pfsense,BlackstarGroup/pfsense,BlackstarGroup/pfsense,NOYB/pfsense,NewEraCracker/pfsense,BlackstarGroup/pfsense,jxmx/pfsense,pfsense/pfsense,dennypage/pfsense,phil-davis/pfsense,ch1c4um/pfsense,jxmx/pfsense,NOYB/pfsense,NewEraCracker/pfsense,jxmx/pfsense,phil-davis/pfsense,pfsense/pfsense,ch1c4um/pfsense,dennypage/pfsense,brunostein/pfsense,phil-davis/pfsense,brunostein/pfsense