Измените

 

Warning: imagepng(/var/www/mojaopstina.rs/www-root/public/images/captcha/05b9d10926de9c22f7ff4528d4152b5e.png): failed to open stream: Permission denied in /var/www/mojaopstina.rs/www-root/library/Zend/Captcha/Image.php on line 563