Fix GDPR account content module

Content modules could not handle array values.  This modifies
modules_content to match the modules behavior.

Also allows select_multiple to accept an id/text array like the
select menu does.

Both these changes together allow the GDPR module to work.  In
particular, they allow country selection to work.

admin/includes/classes/config.php

@@ -52,14 +52,15 @@ public static function select_multiple($selections, $key_values, $key_name = nul
       $string = '';
       foreach ($selections as $key => $text) {
         if (is_int($key)) {
-          $key = $text;
+          if (is_array($text)) {
+            $key = $text['id'];
+            $text = $text['text'];
+          } else {
+            $key = $text;
+          }
         }
 
-        if (isset($key_values[$key]) || array_key_exists($key, $key_values)) {
-          $checkbox->tick();
-        } else {
-          $checkbox->delete('checked');
-        }
+        $checkbox->tick(isset($key_values[$key]) || array_key_exists($key, $key_values));
 
         $string .= PHP_EOL . '<br><label>' . $checkbox->set('value', $key) . ' ' . $text . '</label>';
       }

admin/modules_content.php

@@ -98,6 +98,10 @@ function _sortContentModuleFiles($a, $b) {
         foreach ( $modules['installed'] as $m ) {
           if ( $m['code'] == $class ) {
             foreach ($_POST['configuration'] as $key => $value) {
+              if (is_array($value)) {
+                $value = implode(';', array_map('Text::prepare', $value));
+              }
+
               $key = tep_db_prepare_input($key);
               $value = tep_db_prepare_input($value);