fixes import bug where `num_genomes_total` was null in case of singletons
fixes import bug where `num_genomes_total` was null in case of singletons

EBI-Metagenomics/emgapi,EBI-Metagenomics/emgapi,EBI-Metagenomics/emgapi,EBI-Metagenomics/emgapi,EBI-Metagenomics/emgapi