Only check for active registrations when inviting
Only check for active registrations when inviting

If a registration is not active anymore it makes sense to allow the user
to be invited again.

OmeGak/indico,ThiefMaster/indico,mvidalgarcia/indico,pferreir/indico,indico/indico,OmeGak/indico,ThiefMaster/indico,ThiefMaster/indico,DirkHoffmann/indico,DirkHoffmann/indico,mic4ael/indico,indico/indico,indico/indico,mvidalgarcia/indico,mvidalgarcia/indico,OmeGak/indico,mic4ael/indico,OmeGak/indico,pferreir/indico,pferreir/indico,pferreir/indico,mvidalgarcia/indico,DirkHoffmann/indico,ThiefMaster/indico,mic4ael/indico,indico/indico,DirkHoffmann/indico,mic4ael/indico