Including the `Range` header on S3 requests triggers a `502 Bad Gateway` when localstack is run with SSL.

Sample test that demonstrates the issue:
```python
import logging
import io
import os

import boto3

logging.basicConfig(level=logging.INFO)


def test_range_s3():
    s3 = boto3.client('s3', endpoint_url='https://localhost:4572', use_ssl=True, verify=False)

    bucket = 'localstack-s3-range'
    obj_name = 'sample.bin'
    s3.create_bucket(Bucket=bucket)

    chunk_size = 1024

    with io.BytesIO() as data:
        data.write(os.urandom(chunk_size * 2))
        logging.info('Uploading object (size=%d)', data.getbuffer().nbytes)
        data.seek(0)
        s3.upload_fileobj(data, bucket, obj_name)

    range_header = f'bytes=0-{chunk_size - 1}'
    logging.info('Downloading using Range header: %s', range_header)
    
    # this will raise an exception
    # botocore.exceptions.ClientError: An error occurred (502) when calling the GetObject operation (reached max retries: 4): Bad Gateway
    resp = s3.get_object(Bucket=bucket, Key=obj_name, Range=range_header)
    
    content = resp['Body'].read()
    assert len(content) == chunk_size
```

This is a fairly recent regression:

Running against `localstack/localstack:latest` will fail using SSL but pass without SSL. 
Running against `localstack/localstack:0.10.6` will pass using SSL as well as without SSL.

I am guessing changes from either #1887 or #1906 broke this since those were related to `Range` functionality, but have not bisected to be sure.
return 'x-amz-copy-source' in headers or 'x-amz-copy-source' in path
    def forward_request(self, method, path, data, headers):
        
        parsed_path = urlparse.urlparse(path)
        
        
        if 's3.amazonaws.com' not in headers.get('host', ''):
            headers['host'] = 'localhost'
        
        if 'Content-MD5' in headers and not self.is_s3_copy_request(headers, path):
            response = check_content_md5(data, headers)
            if response is not None:
                return response
        modified_data = None
        
        bucket_name = get_bucket_name(path, headers)
        if method == 'PUT' and not re.match(BUCKET_NAME_REGEX, bucket_name):
            if len(parsed_path.path) <= 1:
                return error_response('Unable to extract valid bucket name. Please ensure that your AWS SDK is ' +
                    'configured to use path style addressing, or send a valid <Bucket>.s3.amazonaws.com "Host" header',
                    'InvalidBucketName', status_code=400)
            return error_response('The specified bucket is not valid.', 'InvalidBucketName', status_code=400)
        
        to_find = to_bytes('<LocationConstraint>us-east-1</LocationConstraint>')
        if data and data.startswith(to_bytes('<')) and to_find in data:
            modified_data = data.replace(to_find, to_bytes(''))