### 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_
import logging
import os
import platform
import re
import socket
import subprocess
import tempfile
import time
from typing import Any, Dict, List, Mapping, Tuple
import six
from boto3 import Session
from localstack.constants import (
    AWS_REGION_US_EAST_1,
    DEFAULT_BUCKET_MARKER_LOCAL,
    DEFAULT_DEVELOP_PORT,
    DEFAULT_LAMBDA_CONTAINER_REGISTRY,
    DEFAULT_PORT_EDGE,
    DEFAULT_SERVICE_PORTS,
    FALSE_STRINGS,
    INSTALL_DIR_INFRA,
    LOCALHOST,
    LOCALHOST_IP,
    LOG_LEVELS,
    TRACE_LOG_LEVELS,