[FIX] Duplicate file delete after request
[FIX] Duplicate file delete after request

 * In case of conflict the file would be added twice to the list and
Indico would try to delete it twice at the end of the request.

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