Don't crash if an existing lineage is slightly corrupt
Don't crash if an existing lineage is slightly corrupt

sjerdo/letsencrypt,DavidGarciaCat/letsencrypt,Bachmann1234/letsencrypt,BillKeenan/lets-encrypt-preview,BKreisel/letsencrypt,VladimirTyrin/letsencrypt,Jadaw1n/letsencrypt,luorenjin/letsencrypt,g1franc/lets-encrypt-preview,Hasimir/letsencrypt,goofwear/letsencrypt,brentdax/letsencrypt,piru/letsencrypt,mrb/letsencrypt,bsmr-misc-forks/letsencrypt,goofwear/letsencrypt,tyagi-prashant/letsencrypt,armersong/letsencrypt,mitnk/letsencrypt,mitnk/letsencrypt,beermix/letsencrypt,deserted/letsencrypt,luorenjin/letsencrypt,lbeltrame/letsencrypt,riseofthetigers/letsencrypt,riseofthetigers/letsencrypt,xgin/letsencrypt,xgin/letsencrypt,kevinlondon/letsencrypt,dietsche/letsencrypt,TheBoegl/letsencrypt,lmcro/letsencrypt,jsha/letsencrypt,kevinlondon/letsencrypt,mrb/letsencrypt,Jadaw1n/letsencrypt,beermix/letsencrypt,hsduk/lets-encrypt-preview,BillKeenan/lets-encrypt-preview,ghyde/letsencrypt,fmarier/letsencrypt,bsmr-misc-forks/letsencrypt,Bachmann1234/letsencrypt,stweil/letsencrypt,DavidGarciaCat/letsencrypt,BKreisel/letsencrypt,martindale/letsencrypt,hsduk/lets-encrypt-preview,thanatos/lets-encrypt-preview,lmcro/letsencrypt,skynet/letsencrypt,TheBoegl/letsencrypt,rlustin/letsencrypt,deserted/letsencrypt,fmarier/letsencrypt,brentdax/letsencrypt,skynet/letsencrypt,lbeltrame/letsencrypt,jtl999/certbot,letsencrypt/letsencrypt,jtl999/certbot,twstrike/le_for_patching,armersong/letsencrypt,wteiken/letsencrypt,kuba/letsencrypt,twstrike/le_for_patching,Hasimir/letsencrypt,thanatos/lets-encrypt-preview,stweil/letsencrypt,letsencrypt/letsencrypt,Sveder/letsencrypt,martindale/letsencrypt,wteiken/letsencrypt,rlustin/letsencrypt,ghyde/letsencrypt,sjerdo/letsencrypt,Sveder/letsencrypt,g1franc/lets-encrypt-preview,dietsche/letsencrypt,VladimirTyrin/letsencrypt,tyagi-prashant/letsencrypt,jsha/letsencrypt,kuba/letsencrypt,piru/letsencrypt