Fix error when using sqlalchemy composite
Fix error when using sqlalchemy composite

We're not using it but it shouldn't be broken anyway.

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