Update seeders list

Summary:
Bitprim's seeders appear to be defunct:

dig seed.bitprim.org
dig testnet-seed.bitprim.org

And I've setup a new seeder. Although the seeder is very new, I transplanted the seed database from a seeder
that has been running for over a year, so the seed quality is already high.

Test Plan:

ninja check
dig seeder.jasonbcox.com
dig -t NS seeder.jasonbcox.com
dig -t SOA seeder.jasonbcox.com

Reviewers: #bitcoin_abc, deadalnix, Mengerian

Reviewed By: #bitcoin_abc, deadalnix, Mengerian

Subscribers: Mengerian

Differential Revision: https://reviews.bitcoinabc.org/D5476