Измените

 

Warning: imagepng(/var/www/mojaopstina.rs/www-root/public/images/captcha/f9595a4e96f951d304bc5c3760eee529.png): failed to open stream: Permission denied in /var/www/mojaopstina.rs/www-root/library/Zend/Captcha/Image.php on line 563