Not working with the newly ap-east-1(Hong Kong) region

[wxdao]

1. What kops version are you running? The command kops version, will display
this information.

Version 1.11.1 (git-0f2aa8d30)

2. What Kubernetes version are you running? kubectl version will print the
version if a cluster is running or provide the Kubernetes version specified as
a kops flag.

Client Version: version.Info{Major:"1", Minor:"14", GitVersion:"v1.14.1", GitCommit:"b7394102d6ef778017f2ca4046abbaa23b88c290", GitTreeState:"clean", BuildDate:"2019-04-08T17:11:31Z", GoVersion:"go1.12.1", Compiler:"gc", Platform:"linux/amd64"}

3. What cloud provider are you using?
AWS
4. What commands did you run? What is the simplest way to reproduce this issue?

kops create cluster --dry-run --output yaml --name toy.hk.k8s.local --cloud=aws --zones=ap-east-1a --state=s3://kops-toy-state-store

5. What happened after the commands executed?

error populating configuration: Region is not a recognized EC2 region: "ap-east-1" (check you have specified valid zones?)

6. What did you expect to happen?

7. Please provide your cluster manifest. Execute
kops get --name my.example.com -o yaml to display your cluster manifest.
You may want to remove your cluster name and other sensitive information.

8. Please run the commands with most verbose logging by adding the -v 10 flag.
Paste the logs into this report, or in a gist and provide the gist link here.

# last lines
I0426 07:19:22.997473   13183 aws_utils.go:64] Querying EC2 for all valid regions

error populating configuration: Region is not a recognized EC2 region: "ap-east-1" (check you have specified valid zones?)

9. Anything else do we need to know?
The output of aws ec2 describe-regions did includes the very region:

...
{
    "Endpoint": "ec2.ap-east-1.amazonaws.com",
    "RegionName": "ap-east-1"
},
...

And running aws ec2 describe-availability-zones --region ap-east-1 caused no problem:

{
    "AvailabilityZones": [
        {
            "State": "available",
            "ZoneName": "ap-east-1a",
            "Messages": [],
            "ZoneId": "ape1-az1",
            "RegionName": "ap-east-1"
        },
        {
            "State": "available",
            "ZoneName": "ap-east-1b",
            "Messages": [],
            "ZoneId": "ape1-az2",
            "RegionName": "ap-east-1"
        },
        {
            "State": "available",
            "ZoneName": "ap-east-1c",
            "Messages": [],
            "ZoneId": "ape1-az3",
            "RegionName": "ap-east-1"
        }
    ]
}