Измените

 

Warning: imagepng(/var/www/mojaopstina.rs/www-root/public/images/captcha/60be69397a30fc9d8f55f822669d1d0d.png): failed to open stream: Permission denied in /var/www/mojaopstina.rs/www-root/library/Zend/Captcha/Image.php on line 563