Измените

 

Warning: imagepng(/var/www/mojaopstina.rs/www-root/public/images/captcha/0627d0be5e3a9f79ba424d38425b5a93.png): failed to open stream: Permission denied in /var/www/mojaopstina.rs/www-root/library/Zend/Captcha/Image.php on line 563