It seems that you need to fix your Virtualmin repos first. This can be done by downloading development version of install.sh script and running it with --setup param, like this:
sh install.sh --setup
Then you can run packages upgrade:
dnf clean all
Need these module to to be enabled to install osticket |;extension=php_intl.dll
Try installing ownCloud script using Install Scripts page, it will install needed PHP extensions for you. Afterwards ownCloud can be uninstalled, while PHP extensions will stay available across the system.