Bug with the ids of the clonable fields.

Greeting everyone,

I have found a bug in the plugin that you might want to take a look at. It concerns cloning groups of fields with WYSIWYG sub fields. If you have the id of the wysiwyg field something like "informatie_dropdown_1_clonable_groep_inhoud" when you clone the field, instead of adding "_1", "_2" and so on at the end of the id of the hidden textarea, it changes the existing "_1" in the id to "_2" and so on.

In my case I addressed the issue by changing the "_1" to a alpha value and everything was ok but in my opinion it is something worth addressing.

Here's a complete code to test and replicate the issue:

$meta_boxes[] = array(
        'id' => 'informatie_dropdown_groep',
        'title' => __('Informatie Dropdown 1 Groep', ''),
        'pages' => array('page'),
        'context' => 'normal', // Where the meta box appear: normal (default), advanced, side. Optional.
        'priority' => 'high',
        'fields' => array(
            array(
                'name' => __('Informatie Groep 1 Titel', ''),
                'desc' => __(''),
                'id' => "{$oyeprefix}informatie_groep_1_title",
                'type' => 'text',
            ),
            array(
                'name' => 'Informatie Dropdown 1', // Optional
                'id' => 'informatie_dropdown_1_clonable_group',
                'type' => 'group',
                'clone' => true,
                'sort_clone' => true,
                'fields' => array(
                    array(
                        'name' => __('Informatie Dropdown 1 Groep Titel', ''),
                        'desc' => __(''),
                        'id' => "{$oyeprefix}informatie_dropdown_1_clonable_groep_titel",
                        'type' => 'text',
                    ),
                    array(
                        'name' => __('Informatie Dropdown 1 Groep Inhoud', ''),
                        'desc' => __(''),
                        'id' => "{$oyeprefix}informatie_dropdown_1_clonable_groep_inhoud",
                        'type' => 'wysiwyg',
                    ),
                )
            ),
            
        )
    );