[IMP] dbi.sync() during redis migration
[IMP] dbi.sync() during redis migration

to avoid using tons of memory

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