there is race condition with zstack-ctl stop_node and start_node
there is race condition with zstack-ctl stop_node and start_node

for https://github.com/zxwing/premium/issues/254

mingjian2049/zstack-utility,zstackio/zstack-utility,zstackio/zstack-utility,live4thee/zstack-utility,live4thee/zstack-utility,zstackio/zstack-utility,mingjian2049/zstack-utility,zstackorg/zstack-utility,mrwangxc/zstack-utility,mingjian2049/zstack-utility,mrwangxc/zstack-utility,zstackorg/zstack-utility,live4thee/zstack-utility,mrwangxc/zstack-utility,zstackorg/zstack-utility