### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

Starting localstack with the CLI `PROVIDER_OVERRIDE_SQS=asf bin/localstack --debug start` starts up correctly but then uses the `default` SQS provider.

### Expected Behavior

I would expect it to start the asf provider.

### How are you starting LocalStack?

With the `localstack` script

### Steps To Reproduce

* `PROVIDER_OVERRIDE_SQS=asf bin/localstack --debug start`
* `awslocal sqs create-queue --queue-name "test-queue"`

logs show:

```
2021-12-27T14:08:43.274:DEBUG:plugin.manager: instantiating plugin PluginSpec(localstack.aws.provider.sqs:default = <function sqs at 0x7f30e6d2b820>)
2021-12-27T14:08:43.274:DEBUG:plugin.manager: loading plugin localstack.aws.provider:sqs:default
2021-12-27T14:08:43.278:INFO:localstack.services.infra: Starting mock SQS service on http port 4566 ...
2021-12-27T14:08:43.279:INFO:localstack.services.infra: Starting mock SQS service on http port 4566 ...
2021-12-27T14:08:43.279:INFO:localstack.services.motoserver: starting moto server on http://0.0.0.0:38335
```

### Environment

```markdown
- OS: Ubuntu 20.04
- LocalStack: 13.2
```


### Anything else?

_No response_
KINESIS_PROVIDER = os.environ.get("KINESIS_PROVIDER") or "kinesis-mock"
if "DEFAULT_REGION" not in os.environ:
    os.environ["DEFAULT_REGION"] = os.environ.get("AWS_DEFAULT_REGION") or AWS_REGION_US_EAST_1
DEFAULT_REGION = os.environ["DEFAULT_REGION"]
SYNCHRONOUS_SNS_EVENTS = is_env_true("SYNCHRONOUS_SNS_EVENTS")
SYNCHRONOUS_SQS_EVENTS = is_env_true("SYNCHRONOUS_SQS_EVENTS")
SYNCHRONOUS_API_GATEWAY_EVENTS = is_env_not_false("SYNCHRONOUS_API_GATEWAY_EVENTS")
SYNCHRONOUS_KINESIS_EVENTS = is_env_not_false("SYNCHRONOUS_KINESIS_EVENTS")
SYNCHRONOUS_DYNAMODB_EVENTS = is_env_not_false("SYNCHRONOUS_DYNAMODB_EVENTS")
KINESIS_ERROR_PROBABILITY = float(os.environ.get("KINESIS_ERROR_PROBABILITY", "").strip() or 0.0)
DYNAMODB_ERROR_PROBABILITY = float(os.environ.get("DYNAMODB_ERROR_PROBABILITY", "").strip() or 0.0)
DYNAMODB_READ_ERROR_PROBABILITY = float(
    os.environ.get("DYNAMODB_READ_ERROR_PROBABILITY", "").strip() or 0.0
)
DYNAMODB_WRITE_ERROR_PROBABILITY = float(
    os.environ.get("DYNAMODB_WRITE_ERROR_PROBABILITY", "").strip() or 0.0
)
DYNAMODB_HEAP_SIZE = os.environ.get("DYNAMODB_HEAP_SIZE", "").strip() or "256m"
HOSTNAME_EXTERNAL = os.environ.get("HOSTNAME_EXTERNAL", "").strip() or LOCALHOST
SQS_PORT_EXTERNAL = int(os.environ.get("SQS_PORT_EXTERNAL") or 0)
LOCALSTACK_HOSTNAME = os.environ.get("LOCALSTACK_HOSTNAME", "").strip() or LOCALHOST
HOSTNAME_FROM_LAMBDA = os.environ.get("HOSTNAME_FROM_LAMBDA", "").strip()
LAMBDA_REMOTE_DOCKER = is_env_true("LAMBDA_REMOTE_DOCKER")
BUCKET_MARKER_LOCAL = (
    os.environ.get("BUCKET_MARKER_LOCAL", "").strip() or DEFAULT_BUCKET_MARKER_LOCAL
)
LAMBDA_DOCKER_NETWORK = os.environ.get("LAMBDA_DOCKER_NETWORK", "").strip()
LAMBDA_DOCKER_DNS = os.environ.get("LAMBDA_DOCKER_DNS", "").strip()
LAMBDA_DOCKER_FLAGS = os.environ.get("LAMBDA_DOCKER_FLAGS", "").strip()
LAMBDA_CONTAINER_REGISTRY = (