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# Type of request: This is a ...

[x] bug report
[ ] feature request

# Detailed description

SNS is unable to forward the message to SQS (non fifo queue) when using the `elasticmq` backend and fails with the following log
```
2021-01-19T09:31:50:WARNING:localstack.services.sns.sns_listener: Unable to forward SNS message to SQS: An error occurred (InvalidParameterValue) when calling the SendMessage operation: Value for parameter MessageGroupId is invalid. The request include parameter that is not valid for this queue type Traceback (most recent call last):

File "/opt/code/localstack/localstack/services/sns/sns_listener.py", line 297, in message_to_subscribers

sqs_client.send_message(

File "/opt/code/localstack/.venv/lib/python3.8/site-packages/botocore/client.py", line 357, in _api_call

return self._make_api_call(operation_name, kwargs)

File "/opt/code/localstack/.venv/lib/python3.8/site-packages/botocore/client.py", line 676, in _make_api_call

raise error_class(parsed_response, operation_name)

botocore.exceptions.ClientError: An error occurred (InvalidParameterValue) when calling the SendMessage operation: Value for parameter MessageGroupId is invalid. The request include parameter that is not valid for this queue type
```
This is likely a regression due to #3435. Tested with the default backend on `0.12.5` and it works as expected. Also works with `elasticmq` backend on `0.12.4`

## Expected behavior

Same behavior with the `elasticmq` backend as with the default backend.

## Actual behavior

Fails on `elasticmq` backend, no SQS message received when SNS message is sent.

# Steps to reproduce

## Command used to start LocalStack

```yaml
  localstack:
    image: localstack/localstack:0.12.5
    ports:
      - 4566:4566
    environment:
      - AWS_DEFAULT_REGION=ap-northeast-1
      - SERVICES=sns,sqs
      - SQS_PROVIDER=elasticmq
```

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

""" Called upon deletion of an SQS queue, to remove the queue from subscriptions """
    for topic_arn, subscriptions in SNS_SUBSCRIPTIONS.items():
        subscriptions = SNS_SUBSCRIPTIONS.get(topic_arn, [])
        for subscriber in list(subscriptions):
            sub_url = subscriber.get('sqs_queue_url') or subscriber['Endpoint']
            if queue_url == sub_url:
                subscriptions.remove(subscriber)
def message_to_subscribers(message_id, message, topic_arn, req_data, subscription_arn=None, skip_checks=False):
    subscriptions = SNS_SUBSCRIPTIONS.get(topic_arn, [])
    for subscriber in list(subscriptions):
        if subscription_arn not in [None, subscriber['SubscriptionArn']]:
            continue
        filter_policy = json.loads(subscriber.get('FilterPolicy') or '{}')
        message_attributes = get_message_attributes(req_data)
        if not skip_checks and not check_filter_policy(filter_policy, message_attributes):
            LOG.info('SNS filter policy %s does not match attributes %s' % (filter_policy, message_attributes))
            continue
        if subscriber['Protocol'] == 'sms':
            event = {
                'topic_arn': topic_arn,
                'endpoint': subscriber['Endpoint'],
                'message_content': req_data['Message'][0]
            }
            SMS_MESSAGES.append(event)