[IMP] Properly handle modifications with disabled sections
[IMP] Properly handle modifications with disabled sections

- If a section is disabled, modifying a registration will clear the values in the section's form

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