Add CURL options in Swish

In some cases there is a need to add options to CURL in order for payments to work

<?php

function swish_additional_curlopt($curlopt)
{
returnarray_merge($curlopt, array(
CURLOPT_SSL_CIPHER_LIST => 'DEFAULT@SECLEVEL=1',
));
}

add_filter('swish_additional_curlopt', 'swish_additional_curlopt');