bugfix: species like "Ancestral sequences" are not in %assembly_lookup
bugfix: species like "Ancestral sequences" are not in %assembly_lookup

ens-lgil/ensembl-rest,helensch/ensembl-rest,ens-lgil/ensembl-rest,willmclaren/ensembl-rest,ens-lgil/ensembl-rest,willmclaren/ensembl-rest,helensch/ensembl-rest,ens-lgil/ensembl-rest,helensch/ensembl-rest,willmclaren/ensembl-rest,willmclaren/ensembl-rest,helensch/ensembl-rest,helensch/ensembl-rest,ens-lgil/ensembl-rest,willmclaren/ensembl-rest