Changes and notes for build requirements
    
    * BuildRequires in proxysql .spec file has been divided and commented to
    increase readibility. Dependencies specificly required/used by
    proxysql code are now marked.
    
    * Few special dependencies like perl, that are only used by additional
    scripts has been also separated.
    
    * systemd requirement has been replaced by systemd-rpm-macros according
    to fedoraproject documentation.
    https://docs.fedoraproject.org/en-US/packaging-guidelines/Scriptlets/#_systemd
    This is ony compatible with RHEL >= 8 or the equivalent version of a fedora.