Измените

 

Warning: imagepng(/var/www/mojaopstina.rs/www-root/public/images/captcha/95a625d1a6660240b36b5e220e1ca9d4.png): failed to open stream: Permission denied in /var/www/mojaopstina.rs/www-root/library/Zend/Captcha/Image.php on line 563