Измените

 

Warning: imagepng(/var/www/mojaopstina.rs/www-root/public/images/captcha/65a3269f450f0536e556a6d331d0b3e5.png): failed to open stream: Permission denied in /var/www/mojaopstina.rs/www-root/library/Zend/Captcha/Image.php on line 563