[FIX] KeyError in epayment module
[FIX] KeyError in epayment module

	- epayment webpage can be browsed by event managers
	- fix#566

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