crimson/osd: only unblock wait_for_active_blocker on replica when ACTIVE

crimson/osd: only unblock wait_for_active_blocker on replica when ACTIVE

ReplicaActive::react(ActivateCommitted) sets ACTIVE or PEERED before
calling on_activate_committed().  Without a guard, an unconditional
unblock() on the PEERED path resets the promise, causing ops that
arrive afterward to park indefinitely (until the next on_change()).

The primary already has this guard in on_activate_complete(); mirror it
on the replica side.

See-also: 2389c32d517e
Signed-off-by: Kefu Chai <k.chai@proxmox.com>