hostapd: ucode: fix setup of a BSS added at run time

hostapd: ucode: fix setup of a BSS added at run time

The 2026-07-09 update changed the type of the first parameter of
hostapd_setup_bss() from int to bool. Before the update, add_bss
passed -1. The value -1 selected the setup path for a secondary BSS
and told hostapd to adopt an existing netdev. Converted to bool, -1
becomes true. As a result, hostapd does not do the setup of a
secondary BSS. The new BSS uses the driver state of the first BSS.

Pass false so the non-first block runs again. In this path,
use_existing is true, and hostapd adopts a netdev that already
exists.

Fixes: 345404476ac8 ("hostapd: update to 2026-07-09")
Signed-off-by: Chad Monroe <chad@monroe.io>
Link: https://github.com/openwrt/openwrt/pull/24651
Signed-off-by: Nick Hainke <vincent@systemli.org>