Using the :latest localstack, attempts to delete an SQS queue fail with the following error logged to the console.

```localstack_1                          | 2020-02-11T19:04:08:ERROR:localstack.services.generic_proxy: Error forwarding request: 'Attribute.1.Value' Traceback (most recent call last):
localstack_1                          |   File "/opt/code/localstack/localstack/services/generic_proxy.py", line 248, in forward
localstack_1                          |     path=path, data=data, headers=forward_headers)
localstack_1                          |   File "/opt/code/localstack/.venv/lib/python3.7/site-packages/localstack_ext/services/sqs/sqs_extended.py", line 30, in forward_request
localstack_1                          |   File "/opt/code/localstack/localstack/services/sqs/sqs_listener.py", line 60, in forward_request
localstack_1                          |     self._set_queue_attributes(queue_url, req_data)
localstack_1                          |   File "/opt/code/localstack/.venv/lib/python3.7/site-packages/localstack_ext/services/sqs/sqs_extended.py", line 73, in _set_queue_attributes
localstack_1                          |   File "/opt/code/localstack/localstack/services/sqs/sqs_listener.py", line 275, in _set_queue_attributes
localstack_1                          |     attrs = self._format_attributes(req_data)
localstack_1                          |   File "/opt/code/localstack/localstack/services/sqs/sqs_listener.py", line 237, in _format_attributes
localstack_1                          |     key_value = req_data[key2][0]
localstack_1                          | KeyError: 'Attribute.1.Value'```

I'm using terraform to manage my SQS queues and the deletion was triggered by renaming the queue.
import re
import uuid
import xmltodict
from moto.sqs.utils import parse_message_attributes
from moto.sqs.models import Message, TRANSPORT_TYPE_ENCODINGS
from six.moves.urllib import parse as urlparse
from six.moves.urllib.parse import urlencode
from requests.models import Request, Response
from localstack import config
from localstack.config import HOSTNAME_EXTERNAL, SQS_PORT_EXTERNAL
from localstack.utils.aws import aws_stack
from localstack.utils.common import to_str, md5, clone
from localstack.utils.analytics import event_publisher
from localstack.services.awslambda import lambda_api
from localstack.services.generic_proxy import ProxyListener
XMLNS_SQS = 'http://queue.amazonaws.com/doc/2012-11-05/'
SUCCESSFUL_SEND_MESSAGE_XML_TEMPLATE = """
    <?xml version="1.0"?>
    <SendMessageResponse xmlns="%s">
        <SendMessageResult>
            <MD5OfMessageAttributes>{message_attr_hash}</MD5OfMessageAttributes>
            <MD5OfMessageBody>{message_body_hash}</MD5OfMessageBody>
            <MessageId>{message_id}</MessageId>
        </SendMessageResult>
        <ResponseMetadata>
            <RequestId>00000000-0000-0000-0000-000000000000</RequestId>
        </ResponseMetadata>
    </SendMessageResponse>
""".strip() % XMLNS_SQS
VALID_ATTRIBUTE_NAMES = ['DelaySeconds', 'MaximumMessageSize', 'MessageRetentionPeriod',