Checkbox is unchecked, but it loads as checked

Some checkbox are loading, with required option. They are not checked at begin. With 'inputCHKChange' function, we should to update checkbox. So it's update checkbox as it's checked or not.

Problem is checkbox are not checked at begin. but during the load they are checked. How could to manage it?

The html:

<fieldset><div class="form-check"><label class="form-check-label"><input onchange="inputCHKChange(this);" type="checkbox" class="form-check-input" name="undefined[]" checked="false" required="">A</label></div><div class="form-check"><label class="form-check-label"><input onchange="inputCHKChange(this);" type="checkbox" class="form-check-input" name="undefined[]" checked="false" required="">B</label></div></fieldset>

The script:

function inputCHKChange(objInput) {
objInput.setAttribute('checked', objInput.checked);
}

Sample on jsfiddle.net