Измените

 

Warning: imagepng(/var/www/mojaopstina.rs/www-root/public/images/captcha/fe4b9ed824ae09ca0d0892b3b4637d44.png): failed to open stream: Permission denied in /var/www/mojaopstina.rs/www-root/library/Zend/Captcha/Image.php on line 563