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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.

import ast
import base64
import json
import uuid
import logging
import traceback
import six
import requests
import xmltodict
from flask import Response as FlaskResponse
from requests.models import Response, Request
from six.moves.urllib import parse as urlparse
from localstack.config import external_service_url
from localstack.constants import TEST_AWS_ACCOUNT_ID, MOTO_ACCOUNT_ID
from localstack.services.awslambda import lambda_api
from localstack.utils.analytics import event_publisher
from localstack.utils.aws import aws_stack
from localstack.utils.aws.aws_responses import response_regex_replace
from localstack.utils.aws.dead_letter_queue import sns_error_to_dead_letter_queue
from localstack.utils.common import parse_request_data, timestamp_millis, short_uid, to_str, to_bytes, start_thread
from localstack.utils.persistence import PersistingProxyListener
LOG = logging.getLogger(__name__)
SNS_SUBSCRIPTIONS = {}
SUBSCRIPTION_STATUS = {}
SNS_TAGS = {}
PLATFORM_ENDPOINT_MESSAGES = {}
SMS_MESSAGES = []
SKIP_PERSISTENCE_ACTIONS = ['Subscribe', 'ConfirmSubscription', 'Unsubscribe']
class ProxyListenerSNS(PersistingProxyListener):