Измените

 

Warning: imagepng(/var/www/mojaopstina.rs/www-root/public/images/captcha/1e2e41e5744e40a34a1d36ca1cea60a3.png): failed to open stream: Permission denied in /var/www/mojaopstina.rs/www-root/library/Zend/Captcha/Image.php on line 563