Измените

 

Warning: imagepng(/var/www/mojaopstina.rs/www-root/public/images/captcha/80a1e62a83af2cbf170c1e3411da0a05.png): failed to open stream: Permission denied in /var/www/mojaopstina.rs/www-root/library/Zend/Captcha/Image.php on line 563