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# Type of request: This is a ...

[x] bug report
[ ] feature request

# Detailed description

Localstack docker run command contains `-p 8080:8080` twice, which results in an error. When running the following command manually, I can successfully run Localstack:

```
docker run -it -e LOCALSTACK_HOSTNAME="localhost" -e TEST_AWS_ACCOUNT_ID="000000000000" -e DEFAULT_REGION="us-east-1" \
-p 443:443 \
-p 4566:4566 \
-p 8081:8081 \
-p 4567-4617:4567-4617 \
-p 8080:8080  \
--rm --privileged --name localstack_main \
-v "/private/var/folders/01/wnz8g_c95fx81w85tpl2dx300000gn/T/localstack:/tmp/localstack" -v "/var/run/docker.sock:/var/run/docker.sock" -e DOCKER_HOST="unix:///var/run/docker.sock" -e HOST_TMP_FOLDER="/private/var/folders/01/wnz8g_c95fx81w85tpl2dx300000gn/T/localstack" "localstack/localstack"
```

**OS:** MacOS Mojave 10.14.6
**Docker version:** Docker version 19.03.8, build afacb8b

## Expected behavior

Running `localstack start` should set up the stack as expected.

## Actual behavior

Running `localstack start` results in the following Docker error:
```
docker: Error response from daemon: Ports are not available: /forwards/expose/port returned unexpected status: 500.
ERRO[0000] error waiting for container: context canceled
```

# Steps to reproduce
1. Install Localstack - `pip install localstack`
2. Run Localstack - `localstack start`
3. Error is displayed

## Command used to start LocalStack
`localstack start`

## Client code (AWS SDK code snippet, or sequence of "awslocal" commands)
N/A

entrypoint = '%s ' % entrypoint if entrypoint else entrypoint
    plugin_run_params = '%s ' % plugin_run_params if plugin_run_params else plugin_run_params
    web_ui_flags = ''
    if config.START_WEB:
        for port in [config.PORT_WEB_UI, config.PORT_WEB_UI_SSL]:
            if not is_mapped(port):
                web_ui_flags += ' -p {port}:{port}'.format(port=port)
    docker_cmd = ('%s run %s%s%s%s%s' +
        '--rm --privileged ' +
        '--name %s ' +
        '%s %s %s ' +
        '-v "%s:/tmp/localstack" -v "%s:%s" ' +
        '-e DOCKER_HOST="unix://%s" ' +
        '-e HOST_TMP_FOLDER="%s" "%s" %s') % (
            config.DOCKER_CMD, interactive, entrypoint, env_str, user_flags, plugin_run_params,
            container_name, web_ui_flags, port_mappings, data_dir_mount,
            config.TMP_FOLDER, config.DOCKER_SOCK, config.DOCKER_SOCK, config.DOCKER_SOCK,
            config.HOST_TMP_FOLDER, image_name, cmd
    )
    mkdir(config.TMP_FOLDER)
    try:
        run('chmod -R 777 "%s"' % config.TMP_FOLDER)
    except Exception:
        pass
    class ShellRunnerThread(threading.Thread):
        def __init__(self, cmd):
            threading.Thread.__init__(self)
            self.daemon = True
            self.cmd = cmd
        def run(self):