Seeder dumps incorrect service flags under these circumstances:

1. When a seed node is provided manually with -overridednsseed
2. When a seed node address is fetched from other seeders

The service flags may be corrected only if the node is re-rumored via getaddr by some other node. This does not happen for situation 1 above unless the node is public facing.
This patch makes version messages set the service bits correctly.

This is a backport of https://github.com/sipa/bitcoin-seeder/commit/a1e93942842316b60685008f589290d5bdde2058

./bitcoind -daemon
./bitcoin-seeder -host=127.0.0.1 -ns=localhost -mbox=thonkle@protonmail.com -port=5555 -overridednsseed=127.0.0.1
cat dnsseed.dump

Result without patch:

127.0.0.1:8333                                      0   1634593390   12.97%   3.41%   1.15%   0.17%   0.04%  709666  00000000  70016 "/Bitcoin ABC:0.24.3(EB32.0)/"

Result with patch:

127.0.0.1:8333                                      0   1634593493   12.97%   3.41%   1.15%   0.17%   0.04%  709666  00000404  70016 "/Bitcoin ABC:0.24.3(EB32.0)/"