Fix abstract submission with no tracks
Fix abstract submission with no tracks

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