net/relayd: Update to 7.4.2024.01.15-p3

This fixes a problem where relayd would flush address tables during a
config reload, even when the tables are unchanged. This can disrupt
incoming connections handled by the configuration.

Approved by: 0mp (implicit)
Sponsored by: Klara, Inc.
Sponsored by: Modirum MDPay
Differential Revision: https://reviews.freebsd.org/D49086