Bug: racount incremented during unicast, may cause less than intended multicast initial rtr adv

[robbat2]

send_ra_forall always increments racount, even if it's doing a unicast response: so if there is a unicast request during the initial period, the counter is incremented, and we might have sent less than the planned number of multicast ads.

Thread where the bug was discovered: https://github.com/radvd-project/radvd/commit/2591d0189257caeaae2057dfed0a260310497a61#commitcomment-67099529