Set WorkerRunner.worker_state earlier in order to prevent potential r…

…ace condition. Fixes #1500.

locust/runners.py

@@ -605,14 +605,14 @@ def __init__(self, environment, master_host, master_port):
         :param master_port: Port to use for connecting to the master
         """
         super().__init__(environment)
+        self.worker_state = STATE_INIT
         self.client_id = socket.gethostname() + "_" + uuid4().hex
         self.master_host = master_host
         self.master_port = master_port
         self.client = rpc.Client(master_host, master_port, self.client_id)
         self.greenlet.spawn(self.heartbeat).link_exception(greenlet_exception_handler)
         self.greenlet.spawn(self.worker).link_exception(greenlet_exception_handler)
         self.client.send(Message("client_ready", None, self.client_id))
-        self.worker_state = STATE_INIT
         self.greenlet.spawn(self.stats_reporter).link_exception(greenlet_exception_handler)
 
         # register listener for when all users have hatched, and report it to the master node