Same services was registered/deregistered failed when the batch register/deregister.

[clhongooo]

• What version of docker are you running?
  18.09.6
• What version of registrator are you running?
  https://github.com/gliderlabs/registrator/tree/da90d170da9dd7e1a8d9a13429d44686dc3d118f
• Did you build a custom version of registrator? If so, what is that image?
  gliderlabs/registrator:master (April 16, 2019)
• What is the exact command you are running your container with?
  a tool calls the docker api to up/down container.
• A log capture of all the docker events before, during, and after the issue.
  a few services has no added/removed log in registrator's container terminal.

Description of the problem:
When I up/down the batch docker containers with a tool, a few services was registered/deregistered fail.
How reproducible:
up/down the batch docker containers, some containers were registered/deregistered fail.