problems with upgrade

hello all
i have a problem with wordpress upgrade update-core.php
due to a limite in server network we can not conenct to ssl websites
so i can not upgrade|update plugins and themes
can you please give me a solution ?
wp-admin/update-core.php?action=do-core-upgrade
how can i change https://downloads.wordpress.org to http://downloads.wordpress.org?

hanging in following link :

Update WordPress

Downloading update from https://downloads.wordpress.org/release/wordpress-4.3.1-no-content.zip…