### Is there an existing issue for this?

- [X] I have searched the existing issues

### Current Behavior

If I run the following Terraform configuration against Localstack with ElasticMQ backend, then the resource creation hangs while ElasticMQ throws exceptions.

```terraform
terraform {
  required_providers {
    aws = "3.50.0"
  }
}

provider "aws" {
  region                      = "eu-west-1"

  access_key                  = "mock_access_key"
  secret_key                  = "mock_secret_key"
  skip_credentials_validation = true
  skip_metadata_api_check     = true
  skip_requesting_account_id  = true

  endpoints {
    sqs            = "http://localhost:4566"
  }
}

resource "aws_sqs_queue" "queue" {
  name  = "foobar"

  tags = {
    NoFoo = ""
  }
}
```

If I run `ncat -l localhost 4566` instead of Locastack, I can see the `Tag.1.Value=` is there.

```
POST / HTTP/1.1
Host: localhost:4566
User-Agent: APN/1.0 HashiCorp/1.0 Terraform/0.12.31 (+https://www.terraform.io) terraform-provider-aws/3.50.0 (+https://registry.terraform.io/providers/hashicorp/aws) aws-sdk-go/1.39.5 (go1.16; linux; amd64)
Content-Length: 382
Authorization: AWS4-HMAC-SHA256 Credential=mock_access_key/20210722/eu-west-1/sqs/aws4_request, SignedHeaders=content-length;content-type;host;x-amz-date, Signature=1a535809020db386c13b4b4169308bd79d81f47edb3922c9a59c4707d7b51061
Content-Type: application/x-www-form-urlencoded; charset=utf-8
X-Amz-Date: 20210722T133950Z
Accept-Encoding: gzip
Connection: close

Action=CreateQueue&Attribute.1.Name=DelaySeconds&Attribute.1.Value=0&Attribute.2.Name=MaximumMessageSize&Attribute.2.Value=262144&Attribute.3.Name=MessageRetentionPeriod&Attribute.3.Value=345600&Attribute.4.Name=ReceiveMessageWaitTimeSeconds&Attribute.4.Value=0&Attribute.5.Name=VisibilityTimeout&Attribute.5.Value=30&QueueName=foobar&Tag.1.Key=NoFoo&Tag.1.Value=&Version=2012-11-05
```

If I exec into the Localstack container and attach `tshark` on ElasticMQ's port then I can see the query param got dropped.
(`tshark -i lo -f "tcp port 52097" -e http.file_data -Tjson`)

```
"Action=CreateQueue&Attribute.1.Name=DelaySeconds&Attribute.1.Value=0&Attribute.2.Name=MaximumMessageSize&Attribute.2.Value=262144&Attribute.3.Name=MessageRetentionPeriod&Attribute.3.Value=345600&Attribute.4.Name=ReceiveMessageWaitTimeSeconds&Attribute.4.Value=0&Attribute.5.Name=VisibilityTimeout&Attribute.5.Value=30&QueueName=foobar&Tag.1.Key=NoFoo&Version=2012-11-05"
```

### Expected Behavior

The SQS queue should be created without error and the tag set with empty value (`""`). 

### How are you starting LocalStack?

With a `docker run` command

### Steps To Reproduce

#### How are you starting localstack (e.g., `bin/localstack` command, arguments, or `docker-compose.yml`)

    docker run --rm -it -p "4566:4566" -e "SERVICES=sqs" -e "DEBUG=1" -e "SQS_PROVIDER=elasticmq" localstack/localstack:0.12.15

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

    terraform init && terraform apply -auto-approve // on the above Terraform snippet put in main.tf

### Environment

```markdown
- OS: Ubuntu 20.04
- LocalStack: 0.12.15
- Terraform: 1.0.2
```


### Anything else?

As ElasticMQ could handle this edge case more gracefully (at least respond with HTTP 400 and not HTTP 500) I also opened in issue there:  https://github.com/softwaremill/elasticmq/issues/511
queue_name = "queue-%s" % short_uid()
        dead_queue_url = self.client.create_queue(QueueName="newQueue")["QueueUrl"]
        supported_attribute_get = self.client.get_queue_attributes(
            QueueUrl=dead_queue_url, AttributeNames=["QueueArn"]
        )
        self.assertTrue("QueueArn" in supported_attribute_get["Attributes"].keys())
        dead_queue_arn = supported_attribute_get["Attributes"]["QueueArn"]
        _redrive_policy = {
            "deadLetterTargetArn": dead_queue_arn,
            "maxReceiveCount": "10",
        }
        attributes = {
            "MessageRetentionPeriod": "604800",
            "DelaySeconds": "10",
            "RedrivePolicy": json.dumps(_redrive_policy),
        }
        queue_url = self.client.create_queue(QueueName=queue_name, Attributes=attributes)[
            "QueueUrl"
        ]