Измените

 

Warning: imagepng(/var/www/mojaopstina.rs/www-root/public/images/captcha/5922e8095250a2d01d9d66d5cf1630a7.png): failed to open stream: Permission denied in /var/www/mojaopstina.rs/www-root/library/Zend/Captcha/Image.php on line 563