Failed to pull image "busybox"

After last fluentd-cloudwatch update I have this in logs.

`kubectl get events -A | grep -i "error\|warning\|failed" | grep fluentd-cloudwatch

Failed to pull image "busybox": rpc error: code = Unknown desc = Error response from daemon: toomanyrequests: You have reached your pull rate limit. You may increase the limit by authenticating and upgrading: https://www.docker.com/increase-rate-limit

amazon-cloudwatch 12m Warning Failed pod/fluentd-cloudwatch-h8q6w Error: ErrImagePull
amazon-cloudwatch 12m Warning Failed pod/fluentd-cloudwatch-h8q6w Error: ImagePullBackOff
amazon-cloudwatch 19m Warning Failed pod/fluentd-cloudwatch-qd8hh Failed to pull image "busybox": rpc error: code = Unknown desc = Error response from daemon: toomanyrequests: You have reached your pull rate limit. You may increase the limit by authenticating and upgrading: https://www.docker.com/increase-rate-limit`

fluentd-cloudwatch could not start anymore.

Could you include variable to use either public AWS ECR repository or private AWS ECR repository?
If the variable was not set use by default busybox docker hub repository.
If the variable was set use repository provided in the variable.

Start with the Kubernetes YAML templates and Dockerfile in the repository, then locate where the fluentd-cloudwatch busybox image is configured. Check how image settings are exposed and use kubectl events to reproduce the pull failure. Done means the default remains the Docker Hub busybox image while a configured public or private AWS ECR repository is used instead.

Written by the indexing model from the issue text.