Измените

 

Warning: imagepng(/var/www/mojaopstina.rs/www-root/public/images/captcha/97fa078b2be3c00a8d8b1f2896483f39.png): failed to open stream: Permission denied in /var/www/mojaopstina.rs/www-root/library/Zend/Captcha/Image.php on line 563