fix minors issues

lib/Subscribers/ImportExport/Export/DynamicSubscribersGetter.php

@@ -11,7 +11,7 @@ use MailPoet\WP\Hooks;
  */
 class DynamicSubscribersGetter extends SubscribersGetter {
 
-  protected $segment_index;
+  protected $segment_index = 0;
 
   public function reset() {
     parent::reset();
@@ -40,7 +40,7 @@ class DynamicSubscribersGetter extends SubscribersGetter {
       ->selectMany(array(
         'list_status' => Subscriber::$_table . '.status'
       ))
-      ->selectExpr("'{$name}' AS segment_name")
+      ->selectExpr("'". $name . "' AS segment_name")
       ->offset($this->offset)
       ->limit($this->batch_size)
       ->findArray();

lib/Subscribers/ImportExport/Export/Export.php

@@ -97,6 +97,7 @@ class Export {
         )
       ) . PHP_EOL
     );
+
     $subscribers = $this->getSubscribers();
     while($subscribers !== false) {
       $processed_subscribers += count($subscribers);

lib/Subscribers/ImportExport/ImportExportFactory.php

@@ -17,11 +17,11 @@ class ImportExportFactory {
     $this->action = $action;
   }
 
-  function getSegments($with_confirmed_subscribers = false) {
+  function getSegments() {
     if($this->action === self::IMPORT_ACTION) {
       $segments = Segment::getSegmentsForImport();
     } else {
-      $segments = Segment::getSegmentsForExport($with_confirmed_subscribers);
+      $segments = Segment::getSegmentsForExport();
       $segments = Hooks::applyFilters('mailpoet_segments_with_subscriber_count', $segments);
       $segments = array_values(array_filter($segments, function($segment) {
         return $segment['subscribers'] > 0;