[seeder] Get rid of pointless wait variable and params

Summary:
As per title

This is a partial backport of bchn#1820
https://gitlab.com/bitcoin-cash-node/bitcoin-cash-node/-/merge_requests/1820/diffs?commit_id=c10b3f01fcf8616c59bf2ddebed9b875f071cd72

Test Plan: ninja & src/seeder/bitcoin-seeder

Reviewers: #bitcoin_abc, Fabien

Reviewed By: #bitcoin_abc, Fabien

Subscribers: Fabien

Differential Revision: https://reviews.bitcoinabc.org/D16904