Измените

 

Warning: imagepng(/var/www/mojaopstina.rs/www-root/public/images/captcha/1d85d38093d2b6c3eda4d8b9af1d759b.png): failed to open stream: Permission denied in /var/www/mojaopstina.rs/www-root/library/Zend/Captcha/Image.php on line 563