Does not remove save data. if, I do uninstall module.

<?php
class ControllerExtensionModuleMytheme extends Controller {

private $error = array();

public function index() {

$language = $this->load->language('extension/module/mytheme');
$data = array_merge($language);

$this->document->setTitle($this->language->get('heading_title'));

$this->load->model('setting/setting');

$this->load->model('tool/image');

if (($this->request->server['REQUEST_METHOD'] == 'POST') && $this->validate()) {
$this->model_setting_setting->editSetting('mytheme', $this->request->post);

$this->session->data['success'] = $this->language->get('text_success');

if(isset($this->request->post['save_stay']) and $this->request->post['save_stay']=1)
$this->response->redirect($this->url->link('extension/module/mytheme', 'user_token=' . $this->session->data['user_token'], true));
else
$this->response->redirect($this->url->link('marketplace/extension', 'user_token=' . $this->session->data['user_token'] . '&type=module', true));

}

$data['text_image_manager'] = 'Image manager';
$data['user_token'] = $this->session->data['user_token'];

if (isset($this->session->data['success'])) {
$data['success'] = $this->session->data['success'];
unset($this->session->data['success']);
} else {
$data['success'] = '';
}

// store config data

$config_data = array(

'mytheme_background_color',
'mytheme_button_color',
'mytheme_powered_text',

);

foreach ($config_data as $conf) {
if (isset($this->request->post[$conf])) {
$data[$conf] = $this->request->post[$conf];
} else {
$data[$conf] = $this->config->get($conf);
}
}


if (isset($this->error['warning'])) {
$data['error_warning'] = $this->error['warning'];
} else {
$data['error_warning'] = '';
}

$data['breadcrumbs'] = array();

$data['breadcrumbs'][] = array(
'text' => $this->language->get('text_home'),
'href' => $this->url->link('common/dashboard', 'user_token=' . $this->session->data['user_token'], true)
);

$data['breadcrumbs'][] = array(
'text' => $this->language->get('text_extension'),
'href' => $this->url->link('marketplace/extension', 'user_token=' . $this->session->data['user_token'] . '&type=module', true)
);

$data['breadcrumbs'][] = array(
'text' => $this->language->get('heading_title'),
'href' => $this->url->link('extension/module/mytheme', 'user_token=' . $this->session->data['user_token'], true)
);


$data['action'] = $this->url->link('extension/module/mytheme', 'user_token=' . $this->session->data['user_token'], true);

$data['cancel'] = $this->url->link('marketplace/extension', 'user_token=' . $this->session->data['user_token'] . '&type=module', true);

if (isset($this->request->post['mytheme_module'])) {
$modules = explode(',', $this->request->post['mytheme_module']);
} elseif ($this->config->get('mytheme_module') != '') {
$modules = explode(',', $this->config->get('mytheme_module'));
} else {
$modules = array();
}

$this->load->model('localisation/language');

$data['languages'] = $this->model_localisation_language->getLanguages();

$data['modules'] = $modules;

if (isset($this->request->post['mytheme_module'])) {
$data['mytheme_module'] = $this->request->post['mytheme_module'];
} else {
$data['mytheme_module'] = $this->config->get('mytheme_module');

}

$data['mytheme_modules'] = array();

$data['header'] = $this->load->controller('common/header');
$data['column_left'] = $this->load->controller('common/column_left');
$data['footer'] = $this->load->controller('common/footer');

$this->response->setOutput($this->load->view('extension/module/mytheme', $data));
}

protected function validate() {
if (!$this->user->hasPermission('modify', 'extension/module/mytheme')) {
$this->error['warning'] = $this->language->get('error_permission');
}

return !$this->error;
}
}