Sort the group by combobox by reference href
Sort the group by combobox by reference href

This way the order won't depend on the order of xccdf Rules in the
content.

OpenSCAP/openscap,jan-cerny/openscap,OpenSCAP/openscap,jan-cerny/openscap,redhatrises/openscap,redhatrises/openscap,Hexadorsimal/openscap,redhatrises/openscap,jan-cerny/openscap,mpreisler/openscap,redhatrises/openscap,OpenSCAP/openscap,Hexadorsimal/openscap,jan-cerny/openscap,OpenSCAP/openscap,mpreisler/openscap,mpreisler/openscap,OpenSCAP/openscap,Hexadorsimal/openscap,mpreisler/openscap,redhatrises/openscap,redhatrises/openscap,OpenSCAP/openscap,jan-cerny/openscap,jan-cerny/openscap,Hexadorsimal/openscap,mpreisler/openscap,mpreisler/openscap,Hexadorsimal/openscap,Hexadorsimal/openscap