“Registered server transport ...” should not be a warning
From register_server_proxy
in src/or/transports.c:
/* LOG_WARN so that the bridge operator can easily find the
transport's port in the log file and send it to the users. */
log_warn(LD_GENERAL, "Registered server transport '%s' at '%s:%d'",
t->name, fmt_addr(&t->addr), (int)t->port);