Измените

 

Warning: imagepng(/var/www/mojaopstina.rs/www-root/public/images/captcha/195a496d6cde63b4bf50b4d905926e8b.png): failed to open stream: Permission denied in /var/www/mojaopstina.rs/www-root/library/Zend/Captcha/Image.php on line 563