Protein abundance endpoint sometimes returns errors when there's no relevant data

[jonrkarr]

Examples:

• Q6Y9H0
  • Returns no data (without organism): https://testapi.datanator.info/proteins/precise_abundance/?uniprot_id=Q6Y9H0
  • 500 error (with organism): https://testapi.datanator.info/proteins/precise_abundance/?uniprot_id=Q6Y9H0&taxon_distance=true&target_species=Saccharomyces%20cerevisiae
• https://testapi.datanator.info/proteins/precise_abundance/?uniprot_id=A0A1T0AW49&taxon_distance=true&target_species=Saccharomyces%20cerevisiae
• https://testapi.datanator.info/proteins/precise_abundance/?uniprot_id=Q41406&taxon_distance=true&target_species=Saccharomyces%20cerevisiae

[lzy7071]

Fixed