fix no default playlist in player setting it to 0

Author: hinanaya

controllers/players.php

@@ -117,7 +117,7 @@ public function save()
 
         $data['timezone'] = trim($this->data('timezone'));
         $data['station_id_image_duration'] = trim($this->data('station_id_image_duration'));
-        $data['default_playlist_id'] = $this->data('default_playlist');
+        $data['default_playlist_id'] = $this->data('default_playlist') ?: null;
 
         $data['parent_player_id'] = $this->data('parent_player_id');
         if (!empty($data['parent_player_id'])) {

models/players_model.php

@@ -322,7 +322,7 @@ public function save($data, $id = false)
 
         $station_id_data['player_id'] = $id;
         if ($station_ids !== false) {
-      // delete all station IDs for this player.
+        // delete all station IDs for this player.
             $this->db->where('player_id', $id);
             $this->db->delete('players_station_ids');