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)
        
        object_key = 'key-by-hostname'
        url = self.s3_client.generate_presigned_url(
            'put_object', Params={'Bucket': bucket_name, 'Key': object_key})
        
        
        url += '&x-amz-meta-foo=bar'
        
        response = requests.put(url, data='content 123', verify=False)
        self.assertLess(response.status_code, 400)
        
        self.assertEqual('', to_str(response.content))
        response = self.s3_client.head_object(Bucket=bucket_name, Key=object_key)
        self.assertEquals('bar', response.get('Metadata', {}).get('foo'))
        
        self._delete_bucket(bucket_name, [object_key])
    def test_s3_get_response_content_type_same_as_upload_and_range(self):