Prevent Requests to "undefined.infinity.json" in touchui-composite-multifield.js

[v-five]

ACS AEM Commons Version: from 4.4.0 to 6.6.2 (latest)
Reproducible on Latest? yes

Actual Behavior

// touchui-composite-multifield.js

addDataInFields: function () {
    var actionUrl = $form.attr("action") + ".infinity.json";

    if (_.isUndefined(actionUrl)) {
        return;
    }

    $.ajax(actionUrl).done(postProcess);
}

Expected Behavior

Check the $form.attr("action") for undefined before the concatenation to avoid requests to "undefined.infinity.json", making the if (_.isUndefined(actionUrl)) check effective.

Steps to Reproduce

View the relevant code on GitHub