When PUTting an S3 object to Localstack with attached Metadata, if a key contains an underscore it is replaced with a dash.

However, when the same request is performed against the real S3, the key is not modified.

Example Input:
key_with_underscores => test

Localstack Result:
key-with-underscores => test

S3 Result:
key_with_underscores => test

Localstack Version: 0.10.5

Tested using AWS v2 S3 client
bucket_name = 'test-bucket-%s' % short_uid()
        self.s3_client.create_bucket(Bucket=bucket_name)
        
        src_key = 'src'
        self.s3_client.put_object(Bucket=bucket_name, Key=src_key, Body='something')
        
        dest_key = 'dest'
        response = self.s3_client.copy_object(Bucket=bucket_name, CopySource={'Bucket': bucket_name, 'Key': src_key},
                                              Key=dest_key)
        self.assertEqual(response['ResponseMetadata']['HTTPStatusCode'], 200)
        
        dest_key2 = 'dest'
        url = self.s3_client.generate_presigned_url(
            'copy_object', Params={'Bucket': bucket_name, 'CopySource': {'Bucket': bucket_name, 'Key': src_key},
                                   'Key': dest_key2}
        )
        
        request_response = requests.put(url, verify=False, headers={'Content-MD5': 'ignored_md5'})
        self.assertEqual(request_response.status_code, 200)
        
        self._delete_bucket(bucket_name, [src_key, dest_key, dest_key2])
    def test_s3_invalid_content_md5(self):