NCBI host fixes needed

On the latest https://nextstrain.org/avian-flu/h5n1-d1.1/genome tree (~200 new sequences cf. yesterday!) <img width="309" alt="Image" src="https://github.com/user-attachments/assets/779ab16c-bc29-4b4e-8452-26572fe47f6a" /> And [in the cattle-outbreak (B3.13) tree](https://nextstrain.org/avian-flu/h5n1-cattle-outbreak/genome), which uses the same NCBI sources: <img width="260" alt="Image" src="https://github.com/user-attachments/assets/1da55e23-7fcc-46df-a009-c9bbdc4137ef" />