[NodeBundle] Refactor online template

[denbatte]

Q	A
Bug fix?	yes
New feature?	no
BC breaks?	no
Deprecations?	no
Fixed tickets

If you wanted to use the 'online template' from the nodebundle, you had to convert the 0 or 1 boolean in database to "true" or "false" strings using.

public function getValue($item, $columnName)
{
    if ($columnName == 'online') {
        return $item['online'] ? 'true' : 'false';
    }

    return parent::getValue($item, $columnName);
} 

This is not needed if you just check for the boolean type true or false in the template, and not the string type.