[Domain Mapping] Bug in domain mapping in version 4.4.3.1 on https making non mapped domains ajax

There is a bug in domain mapping plugin on https in version 4.4.3.1, admin_ajax filter is making https urls to http for non-mapped sub-domains and main site.
Problem is in domain-mapping/classes/Domainmap/Utils.php line no 244, it is getting scheme from database for domain but if domain is not mapped database returns null but there is no check and type casting to integer is being done because of which scheme value becomes 0 which is why it is converting https urls in to http which is creating problems in ajax urls being made using admin_url() function. Please resolved this issue in your next update. Below is the correct code for anyone facing same problem, just replace this code with line no 244:
$check_scheme = $this->_wpdb->get_var( $this->_wpdb->prepare("SELECT `scheme` FROM `" . DOMAINMAP_TABLE_MAP . "` WHERE `domain`=%s", $domain) );
if($check_scheme == null)
$check_scheme = 2;
$force_ssl_on_mapped_domain = self::$_schemes[ $domain ] = (int) $check_scheme;