Измените

 

Warning: imagepng(/var/www/mojaopstina.rs/www-root/public/images/captcha/1ff4e0f603ba3a49ded9d910a1c2153e.png): failed to open stream: Permission denied in /var/www/mojaopstina.rs/www-root/library/Zend/Captcha/Image.php on line 563