Fix. Set correct peer status on HELLO

Suppose we get HELLO with group `CHAT` and status `1`.
If we set peer status and then call `zyre_node_join_peer_group` then
peer status become to `2`.
So we should set status after we call `zyre_node_join_peer_group`.
Merge pull request #219 from moteus/master

Fix. Set correct peer status on HELLO