SN Certmgmt exclude pre processor

pre_processor.js

function checkIfRecordExists(payloadItem) {
    var certGr = new GlideRecord('cmdb_ci_certificate');
    certGr.addQuery('fingerprint', payloadItem.values['fingerprint']);
    certGr.query();
    return certGr.next() ? certGr : "";
}

var rtrn = {};

//parsing the json string to a json object
var payloadObj = JSON.parse(payload);

//put your business logic here
var ignoreListprop = gs.getProperty('sn_disco_certmgmt.my.msca.ignorelist');
var ignoreList = ignoreListprop.toString().split(',');
for (var i = 0; i < payloadObj.items.length; i++) {
    var payloadItem = payloadObj.items[i];
    var certRecordGr = checkIfRecordExists(payloadItem);
    if (!certRecordGr) { //only focus on new records
        //TO EXCLUDE SELECT RECORDS FROM TRACKING BASED ON PROPERTY LOOKUP
        var ignoreListResponse = false; //set default for ignore list
        //check if name is on ignore list
        for (var x = 0; x < ignoreList.length; x++) {
            if (payloadItem.values.subject_common_name == ignoreList[x]) {
                ignoreListResponse = 'true';
            }
        }
        if (ignoreListResponse == 'true') {
            payloadItem.values.renewal_tracking = 'none';
            payloadItem.values.short_description = 'Tracking Disabled by Certificate Ignore List property sn_disco_certmgmt.my.msca.ignorelist';
        } 
    }
}

//you can return a message and a status, on top of the input variables that you MUST return.
//returning the payload as a Json String is mandatory in case of a pre sensor script, and optional in case of post sensor script.
//if you want to terminate the payload processing due to your business logic - you can set isSuccess to false.
rtrn = {
    'status': {
        'message': 'Enter your message here',
        'isSuccess': true
    },
    'patternId': patternId,
    'payload': JSON.stringify(payloadObj)
};