Bug: in ec2SSH, if waitVM fails, the worker will keep retrying forever, irrespective of max_retries in the config

For example, waitVM might fail due to a ping fail or an ssh fail. The worker calls rescheduleJob, but the number of retries for that job is not updated properly, causing it to be rescheduled continuously if it continues to fail. This results in many ec2 instances being created until the server is shut down.