### 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_
os.environ.get("LAMBDA_CONTAINER_REGISTRY", "").strip() or DEFAULT_LAMBDA_CONTAINER_REGISTRY
)
LAMBDA_REMOVE_CONTAINERS = (
    os.environ.get("LAMBDA_REMOVE_CONTAINERS", "").lower().strip() not in FALSE_STRINGS
)
DATA_DIR = os.environ.get("DATA_DIR", "").strip()
TMP_FOLDER = os.path.join(tempfile.gettempdir(), "localstack")
if TMP_FOLDER.startswith("/var/folders/") and os.path.exists("/private%s" % TMP_FOLDER):
    TMP_FOLDER = "/private%s" % TMP_FOLDER
HOST_TMP_FOLDER = os.environ.get("HOST_TMP_FOLDER", TMP_FOLDER)
CACHE_DIR = os.environ.get("CACHE_DIR", os.path.join(TMP_FOLDER, "cache")).strip()
LS_LOG = eval_log_type("LS_LOG")
DEBUG = is_env_true("DEBUG") or LS_LOG in TRACE_LOG_LEVELS
DEVELOP = is_env_true("DEVELOP")
DEVELOP_PORT = int(os.environ.get("DEVELOP_PORT", "").strip() or DEFAULT_DEVELOP_PORT)
WAIT_FOR_DEBUGGER = is_env_true("WAIT_FOR_DEBUGGER")
USE_SSL = is_env_true("USE_SSL")
USE_SINGLE_REGION = is_env_true("USE_SINGLE_REGION")
TF_COMPAT_MODE = is_env_true("TF_COMPAT_MODE")
DEFAULT_ENCODING = "utf-8"
DOCKER_SOCK = os.environ.get("DOCKER_SOCK", "").strip() or "/var/run/docker.sock"
DOCKER_FLAGS = os.environ.get("DOCKER_FLAGS", "").strip()
DOCKER_CMD = os.environ.get("DOCKER_CMD", "").strip() or "docker"
LEGACY_DOCKER_CLIENT = is_env_true("LEGACY_DOCKER_CLIENT")
FORWARD_EDGE_INMEM = True
EDGE_BIND_HOST = os.environ.get("EDGE_BIND_HOST", "").strip() or "127.0.0.1"
EDGE_PORT = int(os.environ.get("EDGE_PORT") or 0) or DEFAULT_PORT_EDGE
EDGE_PORT_HTTP = int(os.environ.get("EDGE_PORT_HTTP") or 0)
EDGE_FORWARD_URL = os.environ.get("EDGE_FORWARD_URL", "").strip()
DOCKER_BRIDGE_IP = os.environ.get("DOCKER_BRIDGE_IP", "").strip()