[FIX] RegForm: getId() of radio field when empty
[FIX] RegForm: getId() of radio field when empty

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