Add check if notebook is still waiting for worker

[pplonski]

Please check if session is still waiting for worker before spinning new worker. I think fix code should be here

mercury/mercury/apps/ws/tasks.py

Lines 62 to 69 in fc0d4b2

	notebook_id = job_params["notebook_id"]
	session_id = job_params["session_id"]
	worker_id = job_params["worker_id"]
	worker_url = f"http://{worker_ip}/start/{notebook_id}/{session_id}/{worker_id}"
	log.info(f"Try to start worker {worker_url}")
	response = requests.get(worker_url, timeout=5)
	log.info(f"Response from worker {response.status_code}")
	if response.status_code == 200: